'Enemies of the People' is a sobering film that delves into the heart of the Cambodian Khmer Rouge.

Directed by Thet Sambath and Rob Lemkin, it screens as part of the Bermuda Documentary Film Festival on Saturday. Mr. Lemkin is the founder and director of Old Street Films.

He has produced and directed more than 50 documentaries and won numerous awards. Mr. Sambath is a senior reporter with the Phnom Penh Post, Cambodia's premier English-language newspaper.

He is widely regarded as one of Cambodia's best investigative reporters and his stories have been syndicated all over the world. Mr. Sambath's father was one of an estimated two million Cambodians who died at the hands of the Khmer Rouge in waves of torture, murder and famine throughout the 1970s.

The Khmer Rouge were followers of the Communist Party of Kampuchea. Under Pol Pot and others, they ruled between 1975 and 1979.

Mr. Sambath's father, a middle income peasant, was killed in 1974 when he refused to give the Khmer Rouge his buffalo. Mr. Sambath's mother, forced to marry a Khmer Rouge militiaman, died in childbirth in 1976. His eldest brother disappeared in 1977 in a party purge in the area.

"When the Khmer Rouge fell in 1979, I escaped, aged ten, to a refugee camp on the Thai border," said Mr. Sambath. "I learned English from American missionaries and eventually started working as a fixer for media organisations in Phnom Penh in the 1990s."

But despite having lived through it, Mr. Sambath never really understood what happened under the Khmer Rouge.

"I read history books, almost all by Westerners, but it still didn't make sense to me: why were so many people killed? It could not be just because the Khmer Rouge were 'bad people'."

In 1998 through his work as a journalist, he got to know the children of some senior Khmer Rouge cadres. For the next four years and much to his wife's annoyance, he spent most weekends visiting the home of the most senior surviving leader, Nuon Chea aka Brother Number Two.

"But he never used to say anything different from what he told Western journalists: 'I was low-ranking', 'I knew nothing', 'I am not a killer'," said Mr. Sambath. "Then one day he said to me, 'Sambath, I trust you, you are the person I would like to tell my story to. Ask me what you want to know.'"

For the next five years he told Mr. Sambath the truth, as he saw it, including all the details of killing.

Throughout this time Mr. Sambath also took pains to create a network of Khmer Rouge killers who would talk to him. "There are thousands of people like these in Cambodia but none had ever confessed and finding them is like looking for a needle in the sea," said Mr. Sambath.

"My last group of sources was the plotters, the people who were trying to overthrow Pol Pot and Nuon Chea.

"Without them you cannot understand the Killing Fields. But again, none of the survivors had ever talked. My sources are country people. The Khmer Rouge were all country people. They don't talk to people from the city, let alone foreigners. I am a country person. I think that's why, in the end, they talk to me. I am one of them."

In 2005 he started to plan a book, but he worried that no one would believe him. So he began tape-recording all his interviews. Then he worried that they would still not believe him, so in 2006 he started videotaping his meetings and interviews. "That same year I met Rob Lemkin and we decided to make this documentary film about my work and the secrets of the Khmer Rouge," said Mr. Sambath.

"Some may say no good can come from talking to killers and dwelling on past horror, but I say these people have sacrificed a lot to tell the truth. In daring to confess they have done good, perhaps the only good thing left. They, and all the killers like them, must be part of the process of reconciliation if my country is to move forward."

'Enemies of the People', winner of 12 major international festival awards, will be screened at the BUEI at 4.15 p.m. on Saturday. Tickets, $15, are available at www.bdatix.bm. A trailer from the film can be seen at www.bermudadocs.com.