REPORTER: Nick Lazaredes
Last December, Alexander Litvinenko was laid to rest in London's Highgate cemetery in a lead-lined coffin. Three months later, and his grieving widow is still coming to terms with his death.
MARINA LITVINENKO, WIDOW: Like a normal human I understood I lost him but itis still be here. It's here. I don't lost him yet.
One of the most active Russian dissidents of his generation, Litvinenko was poisoned with a radioactive cup of tea. Within two weeks, this fit, healthy man had wasted away.
YURI FELSHTINSKY, HISTORIAN: Alexander knew that he was a target. He knew that his killing is probably a matter of time. Unfortunately he thought, like everybody else of course, that they will never try to kill him in London.
A former lieutenant in Russia's Federal Security Bureau, the FSB, Litvinenko was despised by the security forces for exposing their secrets to the world. In this video from a training camp for Russian Special Forces, recruits are using his face for target practise.
REPORTER: When I first heard of Litvinenko's poisoning, I was horrified but not surprised. In 2003, I interviewed and filmed with Alexander Litvinenko over several weeks here in London. At the time I wondered about the effect of his work on his personal safety, but Litvinenko himself was convinced that London was his safe haven.
ALEXANDER LITVINENKO, DATELINE 2003 (Translation): I miss my home, I miss my friends, but I want to use this opportunity to thank England, the country that gave refuge to my family and offered us real protection.
Litvinenko knew better than most that the FSB, the old KGB, played rough. In 1997 he himself was recruited to work as an assassin.
ALEXANDER LITVINENKO, (Translation): Our unit received orders from the top officials of our country to liquidate people found disagreeable.
At first Litvinenko thought the targets were crime bosses, but when he was ordered to kill billionaire Boris Berezovsky, who later became his friend and patron, he rebelled. Along with five of his colleagues, he went public.
ALEXANDER LITVINENKO, (Translation): The FSB structure has been used by some not in the interests of the state according to the constitution but in their own interests.
Shortly after, Litvinenko was fired and then imprisoned.
ALEXANDER LITVINENKO, (Translation): I was sacked on 10 January 1999. It was his personal signature. Personal. My order of dismissal was signed personally by Putin.
Litvinenko had actually met Putin the year before. He told Dateline in 2003 that he'd drawn this flow-chart for the then-FSB director showing links between the security service and organised crime.
ALEXANDER LITVINENKO, (Translation): I told him everything honestly. A few days later I got a ribbing from a pal in Internal Security. You chose the right person to give those papers to. Putin. They are laughing at you, you. You gave him your number. I asked my friend How do you know? He ordered us to monitor it. That means a tap.
After being granted political asylum in Britain, Litvinenko continued to speak out. He accused the FSB of orchestrating a series of bombings in 1999 that killed almost 300 people, and were blamed by the Kremlin on Chechen separatists. Litvinenko always knew he could pay a high price for betraying the secrets of the FSB.
ALEXANDER LITVINENKO, (Translation): To be left alone, I had to recant, to take my statements back. Recant and say, "I'm sorry. I won't do it again, meaning, I won't ever challenge the system again, I won't speak the truth". And...and that's the best case. In the worst case they'd just murder me on my own doorstep, somewhere.
It was the worst-case scenario that came to pass late last year. Walter Litvinenko watched his son die.
WALTER LITVINENKO, FATHER (Translation): All his organs were shot. He bit his lip through. That's how painful it was. He bit his lip through. He gnawed at his lips to deal with it. Just before his death I walked to his bed. "Dad, my coccyx hurts so much," he complained to me. I put my hand under - the bed can be raised but it's slow - I got my hand under to support him and then it all flowed out and his eyes froze.
Within hours of his death a family friend, Alex Goldfarb, read out an extraordinary letter that Litvinenko had written to President Putin from his death bed.
ALEX GOLDFARB, STATEMENT: "You have shown yourself to be as barbaric and ruthless as your most hostile critics have claimed. You may succeed in silencing one man, but the howl of protest from around the world will reverberate, Mr Putin, in your ears for the rest of your life."
VLADIMIR PUTIN, RUSSIAN PRESIDENT, (Translation): The people who did this are not God, while Mr Litvinenko is not Lazarus. It's extremely regrettable that such a tragic event as death is being used for political provocations.
Until a few hours before he died, the doctors at London's University College Hospital had no idea what was killing Litvinenko. But when his urine was tested at Britain's Atomic Weapons Establishment, they found polonium.
PROFESSOR NICK PRIEST, RADIOBIOLOGIST: This material is 64,000 times more radioactive than plutonium but produces the same type of radiation. So you wouldn't taste it, you couldn't see it, you couldn't smell it. There's no way you could detect the fact that there was polonium in your food or in your drink.
Professor Nick Priest helped British detectives investigating Litvinenko's killing. He once worked with Britain's Atomic Energy Authority and he's an expert on nuclear laboratories in the former Soviet Union. He says that once polonium has been detected, it leaves a clear trail for investigators to follow.
PROFESSOR NICK PRIEST: So it's not really like a paper trail, it's more like footprints in the snow because you can see which direction you're travelling in as well. So you can follow back from low levels of contamination to high levels of contamination.
And that's what happened. Retracing Litvinenko's movements, investigators picked up a trail of polonium across London, in restaurants, offices and taxis - but that was just the beginning. The trail led Scotland Yard to Heathrow Airport and straight back to Moscow. Those who'd carried the polonium to Britain and met with Litvinenko left their own radioactive fingerprints.
There are three suspects. Russian security consultant Andrei Lugovoi, his business partner Dmitri Kovtun. And a mystery man using the alias of Vladislav, who arrived in Britain on a false passport. The aircraft these men flew on, the taxis they caught and the hotel rooms they slept in all revealed traces of polonium.
OLEG GORDIEVSKY, (Translation): It is a major operation, the preparation, 10-month.
Oleg Gordievsky is the most important KGB agent to ever defect to Great Britain. He believes that Andrei Lugovoi, a former FSB officer who knew Litvinenko before he defected, was used as bait.
OLEG GORDIEVSKY: About the beginning of the last year, Lugovoi started to come regularly to London. He was obviously cultivating Alexander and he was cultivating using money, promising money.
The highest concentration of polonium was found in room 441 at London's Mayfair Millennium Hotel. Lugovoi and Kovtun checked in to the hotel on October 31 and Litvinenko went up to their room that afternoon. They're joined by a man introduced as Vladislav, another security consultant. At some point, Litvinenko is offered a cup of tea. Detectives believe that this was the delivery point for the fatal dose of polonium. It's thought the mysterious third man was a trained assassin. A few hours later, Litvinenko felt ill.
MARINA LITVINENKO: Nobody knew exactly what it was because when we arrived in hospital to say last words, goodbye to Sasha, they let us go in to the room, because if they knew it is polonium, we never could go in. I could stay with him, I could touch him, I could kiss him.
REPORTER: I'm very sorry, Marina, I'm really sorry.
MARINA LITVINENKO: It's OK. It's OK. It will be with me. No problem.
Armed with the forensic equivalent of a smoking gun, Scotland Yard detectives followed the polonium trail back to Moscow. They wanted to interrogate Andrei Lugovoi and Dmitri Kovtun, but the Russian authorities refused to let them quiz them directly. Lugovoi has denied having anything to do with Litvinenko's death.
ANDREI LUGOVOI, (Translation): No, of course not. Moreover, I'd like to remind you that in the Litvinenko case I figure as a witness, not a suspect.
I've also followed the polonium trail to Moscow. I'm on my way to meet an investigative journalist who's followed the case closely. Igor Korolkov writes for 'Novaya Gazeta' a newspaper that's highly critical of the Kremlin and its secret services.
IGOR KOROLKOV, JOURNALIST (Translation): The fact that authorities are quite reluctant to help Scotland Yard with the Russian-based part of the investigation gives me grounds to think that these people are valuable to us.
Korolkov believes Lugovoi was chosen for an assassination plot because he was trusted by Litvinenko as well as by his friend exiled Russian billionaire Boris Berezovsky.
IGOR KOROLKOV, (Translation): He was somebody they would trust. They were so close that he could put anything in a cup of tea.
In 2001, a few years after he quit the FSB, Lugovoi found himself in jail. It was a serious matter, but Lugovoi was mysteriously released early. Igor Korolkov suspects Lugovoi struck a deal with his former masters at the FSB in which he agreed to go back to work.
IGOR KOROLKOV, (Translation): It's quite possible that the beginning of his way to Litvinenko would be in a cell where he was held during the investigation.
The authorities in Moscow not only refused Scotland Yard access to Lugovoi, they denied that the polonium had come from Russia. In fact almost all of the world's polonium comes from here, the Mayak nuclear industrial plant at the town of Chelyabinsk 65. It remains one of Russia's most tightly guarded secrets. The spokesman for Russia's nuclear program says polonium is only produced for export to the US.
REPORTER: So there is no polonium left over that is kept in some special storage facility? Nothing at all?
SERGEI NOVOKOV, RUSSIAN ATOMIC AGENCY, (Translation): There are no storage facilities and no reserves. None at all.
Sergei Novikov says all of Russia's polonium can be accounted for, and security at the Mayak plant is watertight. In fact it's overseen by the very organisation accused of killing Litvinenko.
SERGEI NOVOKOV, (Translation): The informational, industrial and technological security is provided by all our law enforcement agencies, including the Federal Security Bureau you mentioned.
Incredibly, the Kremlin has suggested that Litvinenko himself supplied the polonium that killed him.
GENNADY GUDKOV, POLITICIAN (Translation): I can give you my personal point of view based on the opinion of my colleagues who worked in secret services.
Gennady Gudkov is a former FSB colonel turned politician who's a regarded as a mouthpiece for Russia's Secret Services. He says Litvinenko was involved in smuggling radioactive material so that Chechen separatists could build a dirty bomb.
GENNADY GUDKOV, (Translation): It's quite possible they were either getting ready to sell radioactive materials or preparing to create the so-called dirty bomb, which is not a myth but today's reality. He might have been a victim of such an operation.
The theory that Litvinenko was some sort of nuclear terrorist is typical of the official reaction to this case in Russia. But although such theories might muddy the waters, the polonium trail still clearly points to Russia, and its secret services.
STANISLAV LEKAREV, FORMER KGB OFFICER: All the evidence was crying that this was designed in Russia.
In the late '50s Stanislav Lekarev worked in a top-secret KGB poisons laboratory.
STANISLAV LEKAREV: But we had this laboratory since the time of Lenin. From 1924, the laboratory exists, secret laboratory, which was creating the poisons which can kill the people, and the deaths will look like natural deaths.
In a remarkable admission, Lekarev told Dateline that Litvinenko was not the first victim of polonium. This is a photo of another KGB defector, Nikolai Khokhlov, who was poisoned at a conference in Frankfurt in 1957. Until now it's always been thought that thallium had been used, but Lekarev claims it was polonium.
STANISLAV LEKAREV: Polonium was used once in the case of Khokhlov. Not...again, not very successfully because Khokhlov was saved by the British physicians but it was proved that it was the case of the Russian hands and the hands of KGB.
But I wanted to follow up on more recent deaths with similar hallmarks to the Litvinenko case.
REPORTER: Thats Khattab?
IGOR KOROLKOV, (Translation): Yes, this is Kivilidi, the banker. Thats Tsepov. That is Kholodov, the journalist. This is Litvinenko and Yandarbiev. These are the people who have something to do with it.
Since Litvinenko's murder, Igor Korolkov has been writing about the possible links between that killing, and other unsolved deaths. One was the death of Russian MP and fierce Kremlin critic Yuri Shchekochikhin, who apparently died from radiation poisoning. Another was that of businessman Roman Tsepov, who was also struck down with a mystery illness.
IGOR KOROLKOV, (Translation): I have managed to find out from the person who saw the results of forensic expertise that a radioactive material was found in his body exceeding the norm by a million times.
The Kremlin was never directly linked to these two deaths but there's no doubt that it was involved in the assassination of the former president of Chechnya, in Qatar in 2004. Two officers from Russian military intelligence, the GRU, were charged with his murder. It was a diplomatic fiasco.
STANISLAV LEKAREV: The people arrested after this action said that they have got the explosive device through the diplomatic post, which means that Russia is using terrorism as a state policy.
In a secret deal with Qatar, the GRU agents returned to Russia to serve their sentence there, but as soon as they arrived home they were set free.
REPORTER: The GRU agents returned to Moscow to a private heroes' welcome, until that time the GRU was the only state organ authorised to perform political assassinations overseas. But the bad publicity from Qatar did little to quell Russia's appetite for revenge, and in 2006, the Russian Duma here behind me passed a new law giving the FSB - the Federal Security Bureau - the same legal status, the right to track down and kill Russia's enemies abroad.
Litvinenko's wife says he was worried about the new law but he was even more rattled in October last year by the murder of a friend. High-profile journalist Anna Politkovskaya was gunned down as she returned home to her Moscow apartment. She had exposed crime and corruption in Chechnya as well as atrocities committed by Russia's special services.
MARINA LITVINENKO: When we received this news, he couldn't believe what happened with Anna. He was shocked.
Litvinenko immediately began investigating Politkovskaya's death, and he was poisoned just a few weeks later. So, did the Kremlin kill Litvinenko to shut him up? Not according to former FSB officer Gennady Gudkov.
GENNADY GUDKOV, (Translation): To say this man could represent any danger to the Russian state is just plainly impossible. It's outside the limits of common logic.
But the use of polonium points to an official operation, according to KGB defector Oleg Gordievsky. He says the FSB convinced Putin there would be no clues pointing to murder.
OLEG GORDIEVSKY: They deceived their President, the Russian word is "presidenti podstavali" which means they put their President in an embarrassing situation because he believed his FSB.
MAN: Vladimir Vladimirovich Putin.
But many believe that beyond the President a far more powerful force exists in Russia. The murders of many Kremlin critics are often collectively blamed on a force known as the siloviki.
REPORTER: The term 'siloviki' refers to Russia's security elite the FSB, the GRU, military generals, police commanders and special forces. Traditionally they're regarded as anti-democratic, hell-bent on keeping Russia under their tight control and influence. Now with the presidential elections looming, some commentators believe that the killing of Alexander Litvinenko is proof that the siloviki are asserting their authority, and sending a message that when it comes to the control of the Kremlin, there's no room for negotiation.
YURI FELSHTINSKY: The FSB is now controls the whole country. The FSB is now controls Russia. And this is the first time in the recent history when the secret service are ruling the country. It's... This is a completely new phenomenon. This never happened before.
A recent survey showed that 78% of MPs and senior public servants previously worked for the intelligence or security services. And Vladimir Putin's recently anointed successor, Sergei Ivanov, is the former deputy director of the FSB.
When Litvinenko met Putin in 1998, he described the nexus he saw between government, the security services and organised crime. Eight years later, the Kremlin's most outspoken critic was finally silenced.
MARINA LITVINENKO: Good luck, take care. Goodbye.
Maybe pain is not so sharp how it was before. Maybe it became just constant pain, like everyday memory. And just...you understand that spring is coming but without Sasha, like new year without him.
WALTER LITVINENKO, (Translation): It's hard to speak about Sasha. He was...he was a very good man. It's not because he was my son. I've lost a diamond of a soul.
Reporter/Camera
NICK LAZAREDES
Editors
WAYNE LOVE
NICK OBRIEN
Subtitling
ELENA MIKHAILIK
Music
VICKI HANSEN
Producers
AMOS COHEN
MARTIN BUTLER
Last December, Alexander Litvinenko was laid to rest in London's Highgate cemetery in a lead-lined coffin. Three months later, and his grieving widow is still coming to terms with his death.
MARINA LITVINENKO, WIDOW: Like a normal human I understood I lost him but itis still be here. It's here. I don't lost him yet.
One of the most active Russian dissidents of his generation, Litvinenko was poisoned with a radioactive cup of tea. Within two weeks, this fit, healthy man had wasted away.
YURI FELSHTINSKY, HISTORIAN: Alexander knew that he was a target. He knew that his killing is probably a matter of time. Unfortunately he thought, like everybody else of course, that they will never try to kill him in London.
A former lieutenant in Russia's Federal Security Bureau, the FSB, Litvinenko was despised by the security forces for exposing their secrets to the world. In this video from a training camp for Russian Special Forces, recruits are using his face for target practise.
REPORTER: When I first heard of Litvinenko's poisoning, I was horrified but not surprised. In 2003, I interviewed and filmed with Alexander Litvinenko over several weeks here in London. At the time I wondered about the effect of his work on his personal safety, but Litvinenko himself was convinced that London was his safe haven.
ALEXANDER LITVINENKO, DATELINE 2003 (Translation): I miss my home, I miss my friends, but I want to use this opportunity to thank England, the country that gave refuge to my family and offered us real protection.
Litvinenko knew better than most that the FSB, the old KGB, played rough. In 1997 he himself was recruited to work as an assassin.
ALEXANDER LITVINENKO, (Translation): Our unit received orders from the top officials of our country to liquidate people found disagreeable.
At first Litvinenko thought the targets were crime bosses, but when he was ordered to kill billionaire Boris Berezovsky, who later became his friend and patron, he rebelled. Along with five of his colleagues, he went public.
ALEXANDER LITVINENKO, (Translation): The FSB structure has been used by some not in the interests of the state according to the constitution but in their own interests.
Shortly after, Litvinenko was fired and then imprisoned.
ALEXANDER LITVINENKO, (Translation): I was sacked on 10 January 1999. It was his personal signature. Personal. My order of dismissal was signed personally by Putin.
Litvinenko had actually met Putin the year before. He told Dateline in 2003 that he'd drawn this flow-chart for the then-FSB director showing links between the security service and organised crime.
ALEXANDER LITVINENKO, (Translation): I told him everything honestly. A few days later I got a ribbing from a pal in Internal Security. You chose the right person to give those papers to. Putin. They are laughing at you, you. You gave him your number. I asked my friend How do you know? He ordered us to monitor it. That means a tap.
After being granted political asylum in Britain, Litvinenko continued to speak out. He accused the FSB of orchestrating a series of bombings in 1999 that killed almost 300 people, and were blamed by the Kremlin on Chechen separatists. Litvinenko always knew he could pay a high price for betraying the secrets of the FSB.
ALEXANDER LITVINENKO, (Translation): To be left alone, I had to recant, to take my statements back. Recant and say, "I'm sorry. I won't do it again, meaning, I won't ever challenge the system again, I won't speak the truth". And...and that's the best case. In the worst case they'd just murder me on my own doorstep, somewhere.
It was the worst-case scenario that came to pass late last year. Walter Litvinenko watched his son die.
WALTER LITVINENKO, FATHER (Translation): All his organs were shot. He bit his lip through. That's how painful it was. He bit his lip through. He gnawed at his lips to deal with it. Just before his death I walked to his bed. "Dad, my coccyx hurts so much," he complained to me. I put my hand under - the bed can be raised but it's slow - I got my hand under to support him and then it all flowed out and his eyes froze.
Within hours of his death a family friend, Alex Goldfarb, read out an extraordinary letter that Litvinenko had written to President Putin from his death bed.
ALEX GOLDFARB, STATEMENT: "You have shown yourself to be as barbaric and ruthless as your most hostile critics have claimed. You may succeed in silencing one man, but the howl of protest from around the world will reverberate, Mr Putin, in your ears for the rest of your life."
VLADIMIR PUTIN, RUSSIAN PRESIDENT, (Translation): The people who did this are not God, while Mr Litvinenko is not Lazarus. It's extremely regrettable that such a tragic event as death is being used for political provocations.
Until a few hours before he died, the doctors at London's University College Hospital had no idea what was killing Litvinenko. But when his urine was tested at Britain's Atomic Weapons Establishment, they found polonium.
PROFESSOR NICK PRIEST, RADIOBIOLOGIST: This material is 64,000 times more radioactive than plutonium but produces the same type of radiation. So you wouldn't taste it, you couldn't see it, you couldn't smell it. There's no way you could detect the fact that there was polonium in your food or in your drink.
Professor Nick Priest helped British detectives investigating Litvinenko's killing. He once worked with Britain's Atomic Energy Authority and he's an expert on nuclear laboratories in the former Soviet Union. He says that once polonium has been detected, it leaves a clear trail for investigators to follow.
PROFESSOR NICK PRIEST: So it's not really like a paper trail, it's more like footprints in the snow because you can see which direction you're travelling in as well. So you can follow back from low levels of contamination to high levels of contamination.
And that's what happened. Retracing Litvinenko's movements, investigators picked up a trail of polonium across London, in restaurants, offices and taxis - but that was just the beginning. The trail led Scotland Yard to Heathrow Airport and straight back to Moscow. Those who'd carried the polonium to Britain and met with Litvinenko left their own radioactive fingerprints.
There are three suspects. Russian security consultant Andrei Lugovoi, his business partner Dmitri Kovtun. And a mystery man using the alias of Vladislav, who arrived in Britain on a false passport. The aircraft these men flew on, the taxis they caught and the hotel rooms they slept in all revealed traces of polonium.
OLEG GORDIEVSKY, (Translation): It is a major operation, the preparation, 10-month.
Oleg Gordievsky is the most important KGB agent to ever defect to Great Britain. He believes that Andrei Lugovoi, a former FSB officer who knew Litvinenko before he defected, was used as bait.
OLEG GORDIEVSKY: About the beginning of the last year, Lugovoi started to come regularly to London. He was obviously cultivating Alexander and he was cultivating using money, promising money.
The highest concentration of polonium was found in room 441 at London's Mayfair Millennium Hotel. Lugovoi and Kovtun checked in to the hotel on October 31 and Litvinenko went up to their room that afternoon. They're joined by a man introduced as Vladislav, another security consultant. At some point, Litvinenko is offered a cup of tea. Detectives believe that this was the delivery point for the fatal dose of polonium. It's thought the mysterious third man was a trained assassin. A few hours later, Litvinenko felt ill.
MARINA LITVINENKO: Nobody knew exactly what it was because when we arrived in hospital to say last words, goodbye to Sasha, they let us go in to the room, because if they knew it is polonium, we never could go in. I could stay with him, I could touch him, I could kiss him.
REPORTER: I'm very sorry, Marina, I'm really sorry.
MARINA LITVINENKO: It's OK. It's OK. It will be with me. No problem.
Armed with the forensic equivalent of a smoking gun, Scotland Yard detectives followed the polonium trail back to Moscow. They wanted to interrogate Andrei Lugovoi and Dmitri Kovtun, but the Russian authorities refused to let them quiz them directly. Lugovoi has denied having anything to do with Litvinenko's death.
ANDREI LUGOVOI, (Translation): No, of course not. Moreover, I'd like to remind you that in the Litvinenko case I figure as a witness, not a suspect.
I've also followed the polonium trail to Moscow. I'm on my way to meet an investigative journalist who's followed the case closely. Igor Korolkov writes for 'Novaya Gazeta' a newspaper that's highly critical of the Kremlin and its secret services.
IGOR KOROLKOV, JOURNALIST (Translation): The fact that authorities are quite reluctant to help Scotland Yard with the Russian-based part of the investigation gives me grounds to think that these people are valuable to us.
Korolkov believes Lugovoi was chosen for an assassination plot because he was trusted by Litvinenko as well as by his friend exiled Russian billionaire Boris Berezovsky.
IGOR KOROLKOV, (Translation): He was somebody they would trust. They were so close that he could put anything in a cup of tea.
In 2001, a few years after he quit the FSB, Lugovoi found himself in jail. It was a serious matter, but Lugovoi was mysteriously released early. Igor Korolkov suspects Lugovoi struck a deal with his former masters at the FSB in which he agreed to go back to work.
IGOR KOROLKOV, (Translation): It's quite possible that the beginning of his way to Litvinenko would be in a cell where he was held during the investigation.
The authorities in Moscow not only refused Scotland Yard access to Lugovoi, they denied that the polonium had come from Russia. In fact almost all of the world's polonium comes from here, the Mayak nuclear industrial plant at the town of Chelyabinsk 65. It remains one of Russia's most tightly guarded secrets. The spokesman for Russia's nuclear program says polonium is only produced for export to the US.
REPORTER: So there is no polonium left over that is kept in some special storage facility? Nothing at all?
SERGEI NOVOKOV, RUSSIAN ATOMIC AGENCY, (Translation): There are no storage facilities and no reserves. None at all.
Sergei Novikov says all of Russia's polonium can be accounted for, and security at the Mayak plant is watertight. In fact it's overseen by the very organisation accused of killing Litvinenko.
SERGEI NOVOKOV, (Translation): The informational, industrial and technological security is provided by all our law enforcement agencies, including the Federal Security Bureau you mentioned.
Incredibly, the Kremlin has suggested that Litvinenko himself supplied the polonium that killed him.
GENNADY GUDKOV, POLITICIAN (Translation): I can give you my personal point of view based on the opinion of my colleagues who worked in secret services.
Gennady Gudkov is a former FSB colonel turned politician who's a regarded as a mouthpiece for Russia's Secret Services. He says Litvinenko was involved in smuggling radioactive material so that Chechen separatists could build a dirty bomb.
GENNADY GUDKOV, (Translation): It's quite possible they were either getting ready to sell radioactive materials or preparing to create the so-called dirty bomb, which is not a myth but today's reality. He might have been a victim of such an operation.
The theory that Litvinenko was some sort of nuclear terrorist is typical of the official reaction to this case in Russia. But although such theories might muddy the waters, the polonium trail still clearly points to Russia, and its secret services.
STANISLAV LEKAREV, FORMER KGB OFFICER: All the evidence was crying that this was designed in Russia.
In the late '50s Stanislav Lekarev worked in a top-secret KGB poisons laboratory.
STANISLAV LEKAREV: But we had this laboratory since the time of Lenin. From 1924, the laboratory exists, secret laboratory, which was creating the poisons which can kill the people, and the deaths will look like natural deaths.
In a remarkable admission, Lekarev told Dateline that Litvinenko was not the first victim of polonium. This is a photo of another KGB defector, Nikolai Khokhlov, who was poisoned at a conference in Frankfurt in 1957. Until now it's always been thought that thallium had been used, but Lekarev claims it was polonium.
STANISLAV LEKAREV: Polonium was used once in the case of Khokhlov. Not...again, not very successfully because Khokhlov was saved by the British physicians but it was proved that it was the case of the Russian hands and the hands of KGB.
But I wanted to follow up on more recent deaths with similar hallmarks to the Litvinenko case.
REPORTER: Thats Khattab?
IGOR KOROLKOV, (Translation): Yes, this is Kivilidi, the banker. Thats Tsepov. That is Kholodov, the journalist. This is Litvinenko and Yandarbiev. These are the people who have something to do with it.
Since Litvinenko's murder, Igor Korolkov has been writing about the possible links between that killing, and other unsolved deaths. One was the death of Russian MP and fierce Kremlin critic Yuri Shchekochikhin, who apparently died from radiation poisoning. Another was that of businessman Roman Tsepov, who was also struck down with a mystery illness.
IGOR KOROLKOV, (Translation): I have managed to find out from the person who saw the results of forensic expertise that a radioactive material was found in his body exceeding the norm by a million times.
The Kremlin was never directly linked to these two deaths but there's no doubt that it was involved in the assassination of the former president of Chechnya, in Qatar in 2004. Two officers from Russian military intelligence, the GRU, were charged with his murder. It was a diplomatic fiasco.
STANISLAV LEKAREV: The people arrested after this action said that they have got the explosive device through the diplomatic post, which means that Russia is using terrorism as a state policy.
In a secret deal with Qatar, the GRU agents returned to Russia to serve their sentence there, but as soon as they arrived home they were set free.
REPORTER: The GRU agents returned to Moscow to a private heroes' welcome, until that time the GRU was the only state organ authorised to perform political assassinations overseas. But the bad publicity from Qatar did little to quell Russia's appetite for revenge, and in 2006, the Russian Duma here behind me passed a new law giving the FSB - the Federal Security Bureau - the same legal status, the right to track down and kill Russia's enemies abroad.
Litvinenko's wife says he was worried about the new law but he was even more rattled in October last year by the murder of a friend. High-profile journalist Anna Politkovskaya was gunned down as she returned home to her Moscow apartment. She had exposed crime and corruption in Chechnya as well as atrocities committed by Russia's special services.
MARINA LITVINENKO: When we received this news, he couldn't believe what happened with Anna. He was shocked.
Litvinenko immediately began investigating Politkovskaya's death, and he was poisoned just a few weeks later. So, did the Kremlin kill Litvinenko to shut him up? Not according to former FSB officer Gennady Gudkov.
GENNADY GUDKOV, (Translation): To say this man could represent any danger to the Russian state is just plainly impossible. It's outside the limits of common logic.
But the use of polonium points to an official operation, according to KGB defector Oleg Gordievsky. He says the FSB convinced Putin there would be no clues pointing to murder.
OLEG GORDIEVSKY: They deceived their President, the Russian word is "presidenti podstavali" which means they put their President in an embarrassing situation because he believed his FSB.
MAN: Vladimir Vladimirovich Putin.
But many believe that beyond the President a far more powerful force exists in Russia. The murders of many Kremlin critics are often collectively blamed on a force known as the siloviki.
REPORTER: The term 'siloviki' refers to Russia's security elite the FSB, the GRU, military generals, police commanders and special forces. Traditionally they're regarded as anti-democratic, hell-bent on keeping Russia under their tight control and influence. Now with the presidential elections looming, some commentators believe that the killing of Alexander Litvinenko is proof that the siloviki are asserting their authority, and sending a message that when it comes to the control of the Kremlin, there's no room for negotiation.
YURI FELSHTINSKY: The FSB is now controls the whole country. The FSB is now controls Russia. And this is the first time in the recent history when the secret service are ruling the country. It's... This is a completely new phenomenon. This never happened before.
A recent survey showed that 78% of MPs and senior public servants previously worked for the intelligence or security services. And Vladimir Putin's recently anointed successor, Sergei Ivanov, is the former deputy director of the FSB.
When Litvinenko met Putin in 1998, he described the nexus he saw between government, the security services and organised crime. Eight years later, the Kremlin's most outspoken critic was finally silenced.
MARINA LITVINENKO: Good luck, take care. Goodbye.
Maybe pain is not so sharp how it was before. Maybe it became just constant pain, like everyday memory. And just...you understand that spring is coming but without Sasha, like new year without him.
WALTER LITVINENKO, (Translation): It's hard to speak about Sasha. He was...he was a very good man. It's not because he was my son. I've lost a diamond of a soul.
Reporter/Camera
NICK LAZAREDES
Editors
WAYNE LOVE
NICK OBRIEN
Subtitling
ELENA MIKHAILIK
Music
VICKI HANSEN
Producers
AMOS COHEN
MARTIN BUTLER