Khmer Rouge leaders

Pol Pot: Died in 1998 Ta Mok: The Butcher, captured and awaiting trial Kang Kek: Chief executioner, in jail awaiting trial Ieng Sary: Foreign minister, pardoned Nuon Chea: Chief political theorist and "Brother Number Two", at liberty Khieu Samphan: Public apologist, at liberty

Although the king's signature establishes the legislation as Cambodian law, further negotiations with the United Nations are necessary to finalise details of the court.

Critics say the trials will be a whitewash, because many of the most notorious Khmer Rouge leaders have already been given amnesty under a deal in the 1990s to end the country's long-running civil war.

But Prime Minister Hun Sen has said that, if handled incorrectly, the trials might re-ignite civil war, especially if Khmer Rouge leaders who gave themselves up under the amnesty deal are prosecuted.

The Khmer Rouge leader, Pol Pot, died in 1998.

UN reservations

Four years ago, Cambodia asked the United Nations for help in establishing a special tribunal to judge the architects of genocide, but agreement on how it should be set up and run has been elusive.

The UN wanted a panel of international judges, sitting outside Cambodia to run the tribunal; the Cambodians wanted only local judges on the panel.

In the end, a compromise was reached.

Under the agreement, trials will be held on Cambodian soil, but the UN is insisting that international standards of justice must be met when trials begin.

Cambodia says it will not change the legislation approved by both Cambodia's houses of parliament whether the UN approves or not.

But the UN insists it will back out of the whole process if it excludes key figures in the Khmer Rouge regime.