"I created a relaxed atmosphere so they didn't suspect what was about to happen", describes one ex-Khmer Rouge soldier. "I saw my uncle in the group. I was scared I would be implicated and die alongside him, so I avoided his glance". Award-winning journalist and genocide survivor, Thet Sambath, is known worldwide for obtaining Khmer Rouge confessions on camera. The evidence he gathered for this report suggests the massacre at Po Chrey may have been the greatest single day atrocity since World War Two, exceeding even Srebrenica. The blank stares and half-smiles of the soldiers jar disturbingly with the horrors they are calmly confessing to. Revisiting a pond that was once over-flowing with bodies, perpetrator In Thoen recalls, "scalps were flying, shredded by bullets. The stench of blood was too strong so I stood upwind". A local farmer remembers how as a young boy he played with the severed heads of his neighbours. Putting these accounts to Nuon Chea, Brother Number 2, he shrugs. "I don't deny it happened. But I didn't know at the time".