The cost of the Khmer Rouge tribunal could nearly double, up to $100 million from $56 million, a source close to the courts said Wednesday. Tribunal officials have begun speaking with donor country representatives about the increased budget, said the source, who spoke on condition of anonymity.

Government officials have said in recent months the tribunal could last into 2010, creating a budget shortfall in an already threadbare process. The courts have so far been unable to establish a Victim's Unit, making it more difficult for complainants to participate in the process.

The tribunal was supposed to last three years. Judges were sworn in in July 2006, but the courts underwent a yearlong delay as Cambodian jurists and their international counterparts disagreed over rules governing the tribunal.

Observers say the tribunal will face budget shortfalls by April 2008.

Tribunal spokesman Reach Sambath declined to comment Wednesday on the projected budget increase, but he said the UN, which is shouldering much of the cost of the tribunal, and the government are studying the budget now.

The tribunal already lacks about $8 million, he said.

Hisham Mousar, a legal expert for the rights group Adhoc who monitors the tribunal, said $100 million was not unreasonable for a tribunal, but the money should be spent transparently.