PHNOM PENH: Thirty years after Phnom Penh fell to the Khmer Rouge, 64-year-old Cambodian Bou Meing takes a trip down memory lane.

His is no ordinary nostalgia.

Now old and wizened, he is returning to Tuol Sleng, the high school which became “Cambodia’s Auschwitz”, where thousands of Pol Pot’s enemies were imprisoned and tortured before being clubbed to death in the Cheoung Ek “Killing Fields” outside the capital.

Bou Meing was one of the lucky ones. As an artist who could churn out portraits of Pol Pot, the ultra-Maoist regime’s reclusive leader, he is one of seven out of an estimated 17,000 Tuol Sleng inmates who lived to tell the tale.

“I was imprisoned upstairs, and then tortured and questioned in a house outside the prison. Then they put salt water on my wounds. I still have the scars,” he says, lifting up his shirt to reveal red streaks across his back.

Such scars — and the accounts of survivors like Bou Meing — are likely to play a major role in a trial of Pol Pot’s top surviving henchmen, which Cambodian and United Nations officials hope will be up and running within the year.

Many wonder why it has taken so long, given the mountains of evidence — often in the form of mass graves and piles of skulls — left behind by Pol Pot’s reign of terror.

“Whenever the Khmer Rouge tribunal happens, I’ll stand as a witness and point to those who arrested me and my wife and I will ask them: ‘Where is my wife?’,” Bou Meing said.

“YEAR ZERO”: When the black-clad Khmer Rouge overran Phnom Penh on April 17, 1975, the besieged city’s residents welcomed them with open arms, hoping it meant the end of Cambodia’s civil war, a tragic sideshow to the US anti-communist conflict in neighbouring Vietnam.