FORMER Khmer Rouge head of state Khieu Samphan is to return to the dock today for a public hearing that will once again see his co-lawyers demand his entire case file be translated into French.

Co-lawyers Sa Sovan and Jacques Verges declared in August that their client's trial could not proceed until thousands of pages of court documents were translated into Verges' native tongue, French.

They are now appealing the court's decision to deny the translation.

Verges, nicknamed the "devil's advocate" for defending notorious figures such as Nazi war crimes suspect Klaus Barbie, claims it is impossible to ensure a fair trial if he cannot understand the charges against his client.

"When we detain someone with no clear explanation of why he was arrested, it is illegal and an abuse of human rights," Verges' counterpart Sa Sovan told the Post Wednesday.

"Our purpose is not to delay the trial. I support my co-lawyer and demand documents be translated into French."

But observers have been more sceptical of the defence team, in particular of Verges, who is known for his abrupt and theatrical defence style.

"This is a defence technique to delay the trial," said Sok Sam Oeun of the Cambodian Defenders Project.