Phnom Penh - An international monitor at Cambodia's UN-backed Khmer Rouge tribunal warned Wednesday that the first trial before the cash-strapped court could run much longer than scheduled because of delays in proceedings. In its weekly report on the progress of the trial of former torture prison chief Kaing Guek Eav, known by his revolutionary alias Duch, the US-based War Crimes Studies Center said the trial had been weighed down by procedural arguments and only a handful of witnesses had been called to testify.

"The initial estimates of the trial completing in 12 weeks now seem somewhat unrealistic," the report said. "Given the chamber is yet to hear an estimated 49 further witnesses, proceedings may continue till at least the end of 2009."

The long-awaited trial began in March, and Duch faces charges of crimes against humanity, torture, premeditated murder and breeches of the Geneva conventions, allegedly committed while he was the warden of the S-21 torture prison during the Khmer Rouge's 1975-1979 rule.

At least 15,000 men, women and children were imprisoned, interrogated and tortured at the school-turned-prison in Phnom Penh's suburbs before being murdered at the Choeung Ek "killing fields" on the outskirts of the capital.

In his opening address at the trial in March, the 66-year-old former mathematics teacher apologized to S-21 victims, their families and the country but asserted that he was merely following the orders of his superiors.

The trial was scheduled to conclude on July 2, but judges made a provision in the schedule to extend the hearing if necessary.

Tribunal spokeswoman Helen Jarvis said she had not read the War Crimes Studies Center report but said judges would release a revised schedule for the trial at the end of the week.

"It is hard to project from the first few weeks how long these things will run, but we are hopeful that the trial will follow the schedule closely," she said.

According to the War Crimes Studies Center, which is based at the University of California at Berkeley, translation errors were also hindering the court's progress.

The court's three official languages are English, French and Khmer.

"Trial proceedings were significantly hindered by the questionable quality of translation this week with international defence counsel Francois Roux raising this as a serious violation of the accused person's right to a fair trial," the report said.

The centre said Roux complained that about 50 per cent of what was being said during last week's proceedings was misinterpreted while Cambodian monitors estimated that about 30 to 40 per cent was misinterpreted.

"It seemed clear this week that the KRT is experiencing problems with translation of a magnitude significantly greater and more troubling than previously experienced by other international justice institutions," the report said. "At points, it was impossible for non-Khmer speakers to understand the meaning of exchanges between the judges and the accused person."

Spokeswoman Helen Jarvis said the court was "working to overcome" translation difficulties and suggested the relative inexperience of the tribunal's Khmer-language interpreters was a factor in the problems.

"Lest we forget that a generation of educated people was wiped out during the Khmer Rouge era, so Cambodia is still recovering from that, and the level of education makes translation resources scarce," she said. "We have a young translation team, and they are doing a very good job."

Duch is one of five former Khmer Rouge leaders facing trial for their alleged roles in the deaths of up to 2 million people through execution, starvation or overwork during the Maoist group's rule.

The tribunal was established in 2006 after a decade of negotiations between the United Nations and the Cambodian government and consists of international and domestic judges, prosecutors and defence lawyers.

The United Nations froze funding for the Cambodian side of the court in July after allegations that domestic staff members were being forced to pay kickbacks to their superiors.

The UN said the funds would remain frozen until the Cambodian government conducted a full investigation into the allegations.

The court's top Cambodian judge said in February that funds for the domestic side had dried up, and staff members were forced to work without salaries until Japan provided emergency funding for April.(dpa)