Nuon Chea's defence team is requesting that the Khmer Rouge tribunal’s Supreme Court Chamber investigate new evidence as it weighs the team’s appeal against their client’s life conviction in August, according to a filing posted yesterday.

In the filing, the team argues that the lower chamber’s failure to solicit evidence from documentary filmmakers Thet Sambath and Rob Lemkin while Case 002/01 was being heard led to the exclusion of evidence that would have absolved Chea of responsibility for some of the regime’s crimes.

Lemkin asserted in an email midtrial that he had evidence that the massacre of ex-Lon Nol regime officials at Tuol Po Chrey had not been ordered by Chea and the Khmer Rouge central command, but the court declined to call him as a witness and made no mention of the email in its judgement.

What’s more, the filing continues, an interview with Sambath conducted after the Case 002/01 verdict indicates the existence of evidence supporting Chea’s past assertions that the crimes of the regime were not part of a master plan, as the court found in its judgment.

In a transcript of the interview included in the filing, Sambath says that, at first, he “did not believe one hundred percent or even ten percent what Nuon Chea had told me” about the regime’s crimes, including Tuol Po Chrey, being the results of factional disputes and undisciplined junior cadres.

“I did not believe what he was telling … [but] I keep doing research until I … struck it lucky, meeting both prison chief and supervisors, spies, i.e. investigators of those killings, and perpetrators – the ones who . . . planned the killings of the people,” Sambath is quoted as saying. “What Nuon Chea had said was true.”

Under the court’s rules, the Supreme Court Chamber is permitted to “examine evidence and call new evidence to determine the issue”, and “parties may submit a request to the Chamber for additional evidence provided it was unavailable at trial and could have been a decisive factor”.