The militia leader denies the charge.

Setback

Moreno-Ocampo in his appeal said: "A decision of such critical importance, impacting so directly on the rights of all parties and participants and related to the very exercise of criminal jurisdiction by the court in its first case must impact on the fair and expeditious conduct of the proceedings."

The halt to his trial that had been due to start on Monday was seen as a major setback for the court set up in 2002 which had been gaining momentum of late after a slow start.

The judges decided to suspend the Lubanga trial because the prosecution could not share UN documents with the defence that could help their case because they were provided on the condition of confidentiality to protect sources in war zones.

They say the prosecution has abused a provision in the court's statute which says it can only use such confidential information as a platform for generating new evidence.

In a filing to the court last week, Moreno-Ocampo said the United Nations had agreed to let the judges view the material and said discussions were going on over lifting the confidentiality restrictions.

"It looks like they're working towards a solution. The judges could now say we're satisfied we can look at these documents. We can go ahead with the trial," Geraldine Mattioli from Human Rights Watch said.

War crimes

As well the Democratic Republic of Congo, the court is also investigating war crimes in Sudan's Darfur region, Uganda and the Central African Republic, but it has only three suspects in custody so far, all from Congo, which include Lubanga and two others.

The court is due to hold a hearing on Friday to confirm charges in its second case against its two other detainees, Germain Katanga and Mathieu Ngudjolo,
both former Congolese militia commanders accused of murder, sexual slavery and using child soldiers.

Experts estimate that 5.4 million people have died in a decade of violence in Congo, mainly through hunger and disease.