While jailed Khmer Rouge leaders Ieng Sary and Ieng Thirith have denied as "100 percent false" charges levied against them by the tribunal courts, experts said Wednesday accusations against them were supported by a wide array of evidence.

Ieng Sary said following his arraignment last week charges of war crimes and crimes against humanity were "unacceptable." Investigators say the charges will stand, though a hearing for pre-trial release is possible.

"Khmer Rouge leaders have escaped their responsibilities for 30 years, and they have refused this for 30 years, not just now," said Youk Chhang, director of the Documentation Center of Cambodia. "Now that we have a Khmer Rouge tribunal, I wonder how they, Ieng Sary and Ieng Thirith, can deny the accusations."

"I think their denial will not survive the accusation and the truth found by the Khmer Rouge tribunal," said Thun Sary, director of the rights group Adhoc.

Long Panhavuth, a tribunal observer for the Open Society Justice Initiative, said Wednesday the two had the right to deny the charges against them.

"But we believe, based on the evidence and documents collected by the co-prosecutors, that Khmer Rouge leaders will be made accountable for what happened during their regime," he said.