Hamilton man Rob Hamill faced his brother's alleged killer in a Cambodian court yesterday, but the former torture camp commandant claims he can not remember him.

Speaking to the Times from Phnom Penh shortly after testifying at the UN-backed trial of Kaing Guek Eav, better known as Duch and the head of the notorious S21 prison camp under Pol Pot's Khymer Rouge regime, Mr Hamill was not surprised by Duch's claim he did not recall Mr Hamill's older brother Kerry.

Kerry Hamill is believed to have been one of a handful of Westerners killed in the camp between 1975 and 1979. Kerry Hamill's yacht strayed into Cambodian waters in 1978, and while exact details of his death remain unknown, he is believed to have been tortured and executed while in S21.

Duch has testified he carried out orders from the regime's late leader Pol Pot, and Mr Hamill said Duch continued with that defence when he gave the equivalent of a victim impact statement in Phnom Penh's Extraordinary Chambers of Courts of Cambodia.

"His out is that he was just taking orders. It was either that, or be killed himself."

An emotionally drained Mr Hamill said there was sense of relief at having made his statement, aimed at court judges and detailing the huge impact of his brother's death on the Hamill family. He was able to make extensive eye contact with Duch, who sat just metres from him.

"It was very difficult, but he was certainly very attentive," Mr Hamill said. "I didn't look at him that much when I was making my statement - I was really looking up at the judges."

Reading his statement from notes, Mr Hamill said he was able to look directly at Duch when he made "a couple of pointed comments", while Mr Hamill's wife Rachel noticed Duch nervously fidgeting during particularly emotional parts of her husband's testimony.

"I had some emotional moments in there," Mr Hamill said of his appearance, which lasted just under an hour. "I was wiping away a few tears as I was telling the story."

"Whenever I said things that were emotionally charged about him (Duch), he was shuffling, pretty nervy..."

Mr Hamill believed Duch to be a "very sharp cookie, playing the court really well". Mr Hamill was able to directly question Duch, and asked him how long his brother was interned for.

"But the answer I got was that he (Duch) didn't know...which was a bit disappointing. He just didn't remember."

"The longer Kerry was in there, the worse it would've been," Mr Hamill said. "I know he was in there for at least two months."

Mr Hamill said Duch recalled Kerry Hamill's British crewmate John Dewhurst, "and he just said they both were killed at the same time".

"He said specifically he remembered the British man, but not my brother. It is disappointing, and I find it hard to believe...they were brought in at the same time, two Westerners."

Mr Hamill said although somewhat surreal, events at the trial had transpired much as he had expected. While he had not neccessarily gained any more information about his brother's death, Mr Hamill said he felt it was significant to represent the estimated 17,000 people killed in the camp, and their families.

Feedback from lawyers participating in the trial was that Mr Hamill's statement and questioning had made a strong impact on the judges.

"It was pretty powerful, being in there, and being part of that. I really felt I got the message across that I wanted to."

The trip to Cambodia for the trial will be an integral part of a documentary on Mr Hamill's search for justice for his brother, entitled Brother No 1.

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