It was the first time a suspect being held in the Tribunal's high-security cell block has committed suicide. The detention center holds 27 other people who are awaiting trial.

Although authorities considered the death a case of suicide, Tribunal officials and Dutch police were conducting separate investigations, Chartier said.

Dokmanovic was awaiting a verdict in his war crimes trial on charges that he played a key role in the 1991 massacre of 200 Croats and non-Serbs. The trial ended last Thursday, and a verdict was expected in two weeks.

Dokmanovic, who had pleaded innocent to all charges,faced a maximum sentence of life imprisonment if convicted. Chartier said Dokmanovic had complained to guards yesterday afternoon that he was not feeling well, and he was placed on a suicide watch. The guards checked on him every half-hour and last saw him alive at 11:30 pm (2130 GMT) yesterday, he said.

It is known that Dokmanovic complained yesterday afternoon at 6 pm (1600 GMT) that ``he was not feeling very well,'' Chartier said. ``The doctor was called in ... And placed him under supervision.'' The lights were on in his cell at that time, but shortly thereafter, Dokmanovic managed to short-circuit the electricity in his cell using an electric razor, and the lights went out, Chartier said.

When a guard next passed by his cell just after midnight, the body was found.Dokmanovic's corpse was taken to a nearby hospital morgue, and his defence attorney was notified, Chartier said. It was not immediately known whether Dokmanovic left a note.

During his trial, Dokmanovic had complained through his lawyersof feeling depressed and had been visited by a psychiatrist, but he never hinted he was suicidal. In fact, he was seen as having a good chance at acquittal because the evidence against him was not overwhelming.

Prosecutors had charged Dokmanovic with six counts of war crimes and crimes against humanity for his alleged participation in the massacre near the town of Vukovar, where he was mayor.

The massacre is widely considered to be the worst atrocity of the 1991 Serb-Croat war. According to prosecutors, the atrocity on November 20, 1991, began at Vukovar's hospital, where hundreds of people had sought refuge after the city fell to forces of the Yugoslav National Army, known as the JNA.