Phnom Penh (AsiaNews/Agencies) – Witnesses at undisclosed locations and little trust in the judges is how Cambodia is starting the trial of the leaders of the bloodthirsty Khmer Rouge regime. Key witnesses have in fact gone into hiding a day after prosecutors began collecting evidence for the long-awaited trial.

Khieu Samphan, former head of state for the Khmer Rouges, left his home on Monday in the middle of the night, going away for several months, a neighbour said. It was not immediately clear if the 75-year-old fled in an attempt to avoid prosecution for atrocities committed during his regime's brutal reign in the 1970s.

Khieu Samphan's daughter, Khieu Rattana, dismissed allegations that her father was trying to flee. "If they want to catch him, they can still do that no matter where he tries to run," she said.

Similarly, at least two former prison guards have left their homes, while three others are reluctant to discuss their roles at Tuol Sleng, the regime's main torture centre, said Youk Chhang, director of the Documentation Centre of Cambodia.

With the trial to begin very soon, guards, as well as many other former regime cadres, fear they might also face trial.

"People still have doubts over what level [of the regime] the court is aiming at. Many were part of the system, so they have a reason to feel uneasy about this stuff," Youk Chhang said.

What is more, questions have been raised about the ties between the current ruling party and government (which controls the judges) and the Khmer Rouges.

Human rights groups are equally worried. "People trust international judges, not Cambodian judges'" said Kek Galabru, who chairs the Cambodian League for the Promotion of Defence and Human Rights.

The 17 Cambodian judges (plus 12 international) are of the focus of attention. Some are not well trained; others were trained in the Soviet Union. Many have been accused of corruption.

Concerns have also been raised over the safety of victims testifying against former Khmer Rouges now living among them. Many observers have warned that lingering terror caused by the regime might discourage many from speaking out in court. Hence, for Youk Chhang, a protection programme for witnesses should be instituted.

Another legacy of the Khmer Rouge era is the number of low- or middle-level Khmer Rouge officials who see themselves as victims of the regime.

One of them is Him Huy, 52, an indefatigable farmer and farmer, but also a former Khmer Rouge executioner.

His words of regret have not however convinced Chum Mey, a truck driver who survived the Tuol Sleg torture centre.

"Prison guards are not victims," he said. "Whilst I was waiting to die, they were waiting to kill."