The Khmer Rouge tribunal is working to speed up pre-trial release hearings for three remaining jailed leaders of the regime, a spokesman said.

"Then things will be moving very fast, and it won't be like earlier," said tribunal spokesman Reach Sambath.

Hisham Mousar, a legal expert for the rights group Adhoc who is monitoring the tribunal, said the speed of the processes depended on the complexities of each Khmer Rouge leader's case.

Cases facing "high politics" could become more complicated and take more time, he said.