A former guard tells the tribunal he witnessed a Westerner being burned alive outside Tuol Sleng.

A FORMER security guard at Tuol Sleng prison told Cambodia's war crimes tribunal on Wednesday that he witnessed a Western prisoner being burned alive inside a pile of car tyres.

Chiem Soeu, 52, who was assigned to a guard post outside the S-21 prison, said three guards took the foreign detainee to a street outside the compound, where they made him sit and put his head and body through the tyres.

"At that time, they burned off the body, but the body was not completely burned because they did not use extra car tyres," said witness Chiem Soeu, who now works as a palm-tree climber.

"I saw the remains of the body the next day, and nobody touched it or took it away," he added.

Chiem Soeu, who was called to testify in the trial of his former boss, Kaing Guek Eav, alias Duch, did not mention the nationality of the prisoner in his testimony.

"I saw the black torso and the black, burnt legs," Chiem Soeu said, adding that he was standing about 20 metres from the site.

"For the time that I stood guard, the car tyre was still burning. I think everything was burned off during the next shift."

Duch, who commanded the torture centre during the regime, has previously admitted to the court that four Westerners were detained at the prison - an American, an Australian, a Briton and a New Zealander.

He said on Wednesday that it had not been his orders to burn the Westerners alive, but rather burn their bodies.

"I was ordered by [Brother No 2] Nuon Chea that the foreign prisoners should be taken out and burned to ashes so as not to leave any remains behind," he said.

"So what he said regarding the burning alive of the prisoner seems to carry no weight. It is hard for me to believe that the prisoner was burned alive."

Jarvis says she has support

Separately, the head of the tribunal's victims' unit, Helen Jarvis, said Wednesday that she believed she still had the support of victims at the court despite her membership in a Leninist party faction in Australia.

Speaking at her first press conference since her appointment in June, Jarvis responded in Khmer - chas - for "yes" when asked if the victims she was representing supported her.

Concerns about Jarvis's appointment were first raised by defence lawyers at the court, who singled out a 2006 statement signed by members of the Leninist Party Faction (LPF) including Jarvis. It proclaimed: "Against the bourgeoisie and their state agencies, we don't respect their laws and their fake moral principles."

Victims and civil parties expressed their concern over the appointment in a letter in June, asking her to explain how a person who subscribed to Marxist-Leninist ideals could represent victims of the same ideals.

"The victims' unit is for victims to speak their voice, and they've said that they're not happy [with Jarvis's appointment]. What else can they do?" director of the Documentation Centre of Cambodia, Youk Chhang, said Wednesday.

Hun Sen praises ECCC staff

Hun Sen praised the Cambodian nationals working at the tribunal, saying that they had "no less" capacity than foreigners working there.

"We should be proud of our judges, prosecutors and lawyers who [have the capacity] to work [there]," he said on Wednesday.

"I do not degrade foreigners, but as a Khmer national, I must be proud of [Khmer] officials at this tribunal," he added.

Lawyers for detained former Khmer Rouge leader Nuon Chea sent a letter to the prime minister this week, however, urging him to explain why his signature was on a memorandum about the selection of tribunal judges.

"What role, if any, did you play in the selection and appointment of the jurists?" lawyers asked in a letter dated Monday. Lawyers are concerned that the memo, which was given to them by a "reliable source", could indicate that the independence of the court was compromised.

ADDITIONAL REPORTING BY SAM RITH