Phnom Penh  - Three decades after he supervised the murders of thousands of men, women and children, the former chairman of the Khmer Rouge's infamous Tuol Sleng torture facility will face trial this week before Cambodia's UN-backed war crimes tribunal.

After years of negotiations, delays and controversies, the long-awaited trial of Kaing Guek Eav, known by his revolutionary name Duch, will begin in Phnom Penh on Tuesday with an initial hearing to choose witnesses and set a date for the trial's next stage.

It is expected to be a highly technical and procedural affair, and Duch will not be called to testify, but that is unlikely to dull its significance for some ordinary Cambodians and victims of the regime hoping to reconcile the horrific past.

As the world turns its eyes towards Cambodia this week, it will also find a tribunal beleaguered by deep divisions between its international and domestic actors, allegations of corruption and government interference, and a growing chorus of international criticism.

The world will see how far this country has come since Pol Pot's genocidal regime brought it to its knees, but also how much work is left to be done.

Up to 2 million people - a quarter of Cambodia's population - died through execution, starvation and overwork during the Khmer Rouge's 1975-79 reign. The ultra-Maoist group sought to transform the country into an agrarian socialist utopia, erase history and begin again at "year zero."

This brutal era led to decades of instability and civil war. the scars of which are visible in Cambodia's virtual one-party state, its dilapidated infrastructure, deep social divisions, and impoverished and predominantly rural population.

Duch is the first of the five detained Khmer Rouge leaders to be indicted for crimes against humanity. Pol Pot died at a remote hideout in 1998, but "Brother Number Two" Nuon Chea, former head of state Khieu Samphan, former foreign minister Ieng Sary and his wife Ieng Thirith have been detained.

At 67, Duch is the youngest of all the detainees and the only to have admitted guilt for his crimes. If convicted, he faces a maximum sentence of life in prison. The born-again Christian and former mathematics teacher's trial has been described as a test case for the court, which has so far only entered the pre-trial phase.

It will not only test the court's experimental structure, but also its integrity and legitimacy against domestic and international criticism. Human rights groups say there are serious problems that could jeopardise the court's integrity and financial security.

The New York-based Open Society Justice Initiative said last week that the court was "plagued by pressing institutional challenges that threaten to prevent it from fulfilling its mandate."

It pointed to an ongoing disagreement between the court's international and Cambodian prosecutors over extending the court's investigation and detaining more former Khmer Rouge leaders. International prosecutors want to extend the investigation, while the Cambodian side say the current number of defendants is sufficient.

Referring to allegations that government interference had dictated the Cambodian prosecutors' position, the report said the court must rely "on law and facts, not politics, in deciding how many suspects will be investigated."

"Currently mired in an internal dispute over the number of suspects to be tried, the court must demonstrate that it can quickly make a reasoned determination, free of political interference and in a transparent manner, on whether to investigate and charge additional suspects beyond the five now in custody," the report said.

It also said unresolved allegations of corruption on the Cambodian side of the court, which led to the UN withholding funding in August last year, also brought the tribunal's transparency and integrity into question.

New York-based Human Rights Watch noted that the UN initially was reluctant to implement the hybrid-court model because "Cambodia's judiciary is widely known for its lack of independence, corruption, and low professional standards."

"By allowing political considerations to block additional indictments, the Khmer Rouge tribunal is failing the most basic test of its independence and its credibility," Sara Colm, a Cambodia-based senior researcher at Human Rights Watch, said.

"The tribunal cannot bring justice to the millions of the Khmer Rouge's victims if it tries only a handful of the most notorious individuals, while scores of former Khmer Rouge officials and commanders remain free."

Despite a sizable public awareness campaign carried out by the tribunal over the past few years, it is possible that few Cambodians will be following this week's hearings.

According to a study conducted in September last year but the Human Rights Center and the University of California, Berkley, found that 85 per cent of Cambodians had little or no knowledge about the Khmer Rouge tribunal. (dpa)