Karadzic accused Judge Alphons Orie of bias and of having a personal stake in his case. He said Judge Orie would convict him to reinforce judgements in earlier cases against Bosnian Serbs and justify "draconian" sentences against them.

"There clearly cannot be any question of impartiality on his part," Karadzic said in a letter dated last Friday to the president of the Yugoslav war crimes tribunal, Fausto Pocar.

Judge Orie presided over Karadzic's plea hearing on July 31, his first appearance in court since his capture in Belgrade after more than a decade in hiding.

Karadzic declined to enter a plea, but must do so when he appears in court again on August 29. If he again declines, a not guilty plea will be entered on his behalf.

Judge Orie, a former criminal lawyer and justice of the Dutch Supreme Court, has been a judge at the UN tribunal since 2001.

Preliminary stages of tribunal cases are conducted by a single judge, but trials are heard by a panel of three. The tribunal has no juries.

Karadzic said Judge Orie had been on the bench in the case of Momcilo Krajisnik, the former Bosnian Serb parliament speaker who is appealing against his 27-year sentence. Karadzic claims Krajisnik is innocent of the charges.

Judge Orie also was on the tribunal that convicted Croatian Serb leader, Milan Babic, who committed suicide in the tribunal's detention unit in 2006, and is currently among the judges trying Serb nationalist leader Vojislav Seselj.

While handing down tough sentences against Serbs, Judge Orie presided in the acquittal of former Kosovo Prime Minister Ramush Haradinaj, an "outcome (that) was incredible," Karadzic said.