Cambodian journalist and film-maker Thet Sambath lost most of his family under the brutal Khmer Rouge regime of the 1970s. He explains how his search for the truth led him to form an unlikely bond with one of the most loathed men in his country - Nuon Chea, number two within the Khmer Rouge regime.
"At the age of eight I was orphaned. In Cambodia at that time there were many thousands of children like me, for this was the age of the Khmer Rouge regime and its Killing Fields.
Growing up in a refugee camp in Thailand, I wanted to be a doctor but I didn't have the money to train. So I started working as a translator and fixer for international aid groups and then for the media. That's how I ended up becoming a journalist.
But throughout all those years, I never stopped asking myself why my parents had died - not the details of their individual deaths but why they were among 1.7 million people who lost their lives during the Khmer Rouge years.
During my almost accidental career I discovered that I'm someone people like to talk to. They trust me. I began to wonder if I could use my new-found talent to persuade people from within the Khmer Rouge to talk.
First I had to find them. I sacrificed many weekends when I could have been at home with my wife and our first child travelling to remote jungle areas to follow leads. I didn't dare tell her what I was doing in those days. I knew she'd be worried for my safety. But also, in those early days, I didn't even really know myself what my project was.
Eventually, I was introduced to a man called Nuon Chea. This man was Pol Pot's deputy, aka Brother Number Two.
Sunglasses and pyjamas
When we first met I remember walking up the steps to the simple wooden hut on stilts where he lived. The old man was there to greet me, wearing pyjamas and sunglasses. His wife signalled for me to sit and offered a drink.
After several minutes he took off his shades and I was able to look into the eyes of the most senior surviving leader of the Khmer Rouge. Nuon Chea was the second-in-command in a regime in which millions of Cambodians lost their lives. My father, my mother and my brother were among them.
But this frail old man seemed kindly and shy. His wife was clearly devoted to him and his grandchildren seemed very happy to play at his feet. I finished my glass of water and hesitantly announced I was trying to find out the truth of what happened when the Khmer Rouge attempted to take the country back to Year Zero.
Nuon Chea put on his sunglasses again. He told me the Killing Fields were a Western fiction and that, in any case, he had no power in the regime. His brief was merely political education.
I returned home to Phnom Penh. But I had the feeling there was much more to this man than met the eye.
The following week I returned. He was surprised to see me, but pleased too. He didn't reveal anything more but a pattern had been established.
For the next four years or so I visited Nuon Chea most weekends. I told him I wanted to know the real story of the Khmer Rouge, that I was working alone and that I was only concerned with the truth. What I didn't tell him was that my family died during his regime, because I didn't want him to think I wanted revenge.
For several years he kept to his story. So I tiptoed around the controversial Killing Fields years of 1975-9. But I knew he was beginning to trust me when, one day, I was allowed to stay alone with him while his wife went shopping. He even let me put him to bed for his afternoon nap.
I could easily have stabbed him to death there and then. Millions of Cambodians might even have been proud of me. But I wasn't there for revenge; I was there for the truth.
During one of our meetings in 2005 he turned to me and said: "Sambath, I have checked you out for many years. Now I trust you. Go ahead, ask me anything you want, I will answer you honestly".
My heart was in my mouth and the hairs on my arm stood on end as I finally asked the question I had been waiting so many years to know the answer to.
"Who made the decision to kill people during the Khmer Rouge regime?" I said. He replied: "Pol Pot and I ….."
So began three years of interviews during which Nuon Chea told me, in amazing and chilling detail, how and why he and Pol Pot decided to kill those they designated enemies of the people. At times I think even he could not believe what he was telling me. He used to say: "Sambath, you are only the third person to know all this, after Pol Pot and me".
I was with him on his last night of freedom, in September 2007. He knew that after 30 years the UN-backed war crimes tribunal was poised to arrest him. It was a sad, solemn evening. I admit I felt hollow in the pit of my stomach at the thought of no longer being able to sit quietly with him, and talk about history and politics, life and family. In the course of our six years of work we had become very affectionate towards each other.
Nuon Chea has been in prison for three years now, awaiting trial for genocide, war crimes and crimes against humanity. The court wants to use my interviews as possible confessional evidence in their trial but so far I and my British collaborator, Rob Lemkin, have refused.
It's not because we are opposed to the trial, or to justice, but because my work with Nuon Chea was not about with whether or not he was guilty. It was about trying to find out the history of this terrible time.
What Nuon Chea told me was a first-hand political insider's account of one of the 20th Century's most horrific and mysterious periods. It is, naturally, a very controversial history. It gave me an understanding of how and why his regime turned to killing and helps me make sense of what happened to me and my country when I was a child.
Of course, it doesn't mean that it was OK to kill, and it doesn't bring my parents back to life. But it does help me to go forward. And I hope it will enable other victims of the regime to face the future.
The court must do its work. After 30 years Cambodians are entitled to justice. But I'll forever be grateful to the frail old man who decided to tell me the truth. For without the truth, we will never have a chance of achieving the reconciliation that I and so many other survivors of the Killing Fields so desperately seek."
Enemies of the People, a film by Thet Sambath and Rob Lemkin, opened on 10 December in London.