The defence for Khieu Samphan argued that the prosecution had failed to establish “individual criminal responsibility” for their client at the Khmer Rouge tribunal yesterday, maintaining their long-held assertion that the former head of state had limited knowledge of the atrocities committed under the regime.

Samphan defender Anita Guisse used key documents presented by the prosecution on Monday to make the case that her client was not aware of the full extent of the situation in Cambodia, despite serving as the president of the country at the time. Both Samphan and former “Brother Number Two” Nuon Chea are on trial for crimes against humanity.

Guisse said the prosecutors had failed to connect her client with the Phnom Kraol security centre, a key crime site in the current Case 002/02.

Guisse referred to the centre – where prisoners were reportedly tortured and killed – as a “nebulous” and “vague” institution, maintaining that telegrams sent between it and the capital did not prove that Samphan had knowledge of the alleged crimes committed there. Guisse also contested the prosecution’s claim that Samphan was in the inner decision-making circle of the Communist Party of Kampuchea.

A passage in Behind the Killing Fields by Gina Chon, portions of which were presented by the prosecution, describes Chea deciding not to tell Samphan that he had been accused of treason. In the passage, Chea says he never informed Samphan of the allegations because he “didn’t think it was necessary”.

Guisse argued the section proved that Samphan was sometimes out of the loop in his own administration.

“Many leaders with important positions within government were not involved in crucial decisions,” Guisse said.

Later, Chea defender Victor Koppe took the floor to ask for scheduling flexibility so an unnamed expert could testify on internal armed conflict within Cambodia – a key element of the Chea team’s defence – linked to the external conflict between Cambodia and Vietnam.

“This particular expert is very important,” Koppe said, adding that the witness could “shed a very different light on the nature of the internal purges” that occurred during the regime.

The prosecution and the civil party team agreed efforts should be made to accommodate the witness.

The trial continues on Thursday with testimony from a civil party in relation to the internal purges.