"He has no complaints. He said he would elaborate on the regime when the trial comes," You Bunleng, a Cambodian investigating judge on the $56 million United Nations-backed tribunal, told Reuters.

Nuon Chea, Pol Pot's right-hand man during the Khmer Rouge's 1975-79 reign of terror, was arrested at his simple wooden home on the Thai border on Wednesday and flown to Phnom Penh by helicopter to face the long-awaited tribunal.

An estimated 1.7 million people died during Pol Pot's Beijing-backed "Year Zero" revolution as his dream of transforming the Southeast Asian nation into an agrarian peasant utopia descended into the nightmare of the "Killing Fields."

Despite many reports in the last five years of the octogenarian guerrilla's imminent demise, court spokesman Reach Sambath said Nuon Chea was in good health and had 24-hour access to medical care to ensure he was fit to stand trial.

"Cambodia has been waiting for nearly 30 years for justice to be done. The court must respond to his needs to ensure he is safe," Reach Sambath said. Nuon Chea was receiving "high-calorie food" to keep him strong, he added.

Turning his back on offers of assistance from high-profile international defense lawyers, Nuon Chea had said he wanted a Cambodian attorney from Battambang, his home town in the west of the country, Reach Sambath said.

After his arraignment on Wednesday, Nuon Chea was taken to a specially built pre-trial detention centre in the court compound on the Western outskirts of Phnom Penh to join its only other inmate, chief Khmer Rouge inquisitor Duch.

The born-again Christian and former teacher ran the capital's infamous S-21 interrogation and torture centre at the former Tuol Sleng highschool.

More than 14,000 prisoners are known to have passed through Tuol Sleng's barbed wire gates. Around 10 lived to tell the tale.

Having confessed to mass murder, Duch is expected to be a key witness against Nuon Chea, as well as former President Khieu Samphan and former Foreign Minister Ieng Sary, two other senior cadres in the sights of prosecutors.

Pol Pot died in the last Khmer Rouge redoubt of Anlong Veng on the Thai border in 1998.

Under Cambodia's essentially French legal system, investigating judges will spend months reviewing prosecution charges against the detainees and compiling evidence.

Only when their work is complete will the defendants appear in court for a full trial.

Source: Reuters