He openly admits he was the one that kidnapped them - it's an absolute disgrace

David Purcell, Friend of David Wilson

Foreign Minister Alexander Downer said he had sought clarification of the decision to clear Chhouk Rin of the kidnap and slaying of Australian David Wilson, 29, Briton Mark Slater, 26, and Frenchman Jean-Michel Braquet, 27.

France and Britain also said they were taking up the case through their ambassadors in the Cambodian capital Phnom Penh.

The French Foreign Ministry urged the Cambodian authorities to appeal against the verdict.

Chhouk Rin: Cleared of murder

Chhouk Rin was accused of leading a gang that seized the three men from a train after halting it with a bomb attack that killed 13 Cambodians in July 1994.

The backpackers were held hostage for six weeks, then beaten to death when an attempt to pay a ransom was botched.

Chhouk Rin was acquitted on the basis of a law that granted an amnesty for all Khmer Rouge members who defected after the organisation was outlawed in July 1994.

The judge refused to rule on his guilt or innocence at Tuesday's hearing at a court in Phnom Penh.

Appeal

The Wilson family's lawyer, Bill Woodrow, said an appeal would be lodged against the court proceedings which he described as "a sham".

France wants the authorities in Cambodia to use all their efforts to appeal the decision

French Foreign Ministry

"The whole trial was carefully orchestrated. It was a disgrace to justice," he told the Australian Broadcasting Corporation.

Mr Downer said he was deeply concerned about the verdict.

"We will look closely at the details of the judgement as it contains a number of technical legal issues which need careful consideration," he added.

"I have instructed our embassy in Phnom Penh to make the highest-level representations to the Cambodian authorities about the matter."

Disgrace

David Purcell, a close friend of Mr Wilson, condemned the verdict.

Millions died during the Khmer Rouge's brutal rule

"He openly admits he was the one that kidnapped them at gunpoint and this guy can walk free - it's an absolute disgrace," he said.

Another senior Khmer Rouge figure, Nuon Paet, was jailed for life last year for his part in the backpacker slayings.

He did not have immunity from prosecution, because he had not surrendered during the amnesty period.