International co-prosecutor Nicholas Koumjian went on the offensive at the Khmer Rouge tribunal yesterday, blasting former regime leader Khieu Samphan for treating his citizens like “farm animals” and personally accusing him of being an active participant in the “killing campaign”.

On Wendesday, Samphan’s defence lawyer Anta Guisse presented key documents she hoped would show her defendant had limited personal responsibility for the crimes committed under his regime. Guisse argued regional leaders acted autonomously, often disobeying central policy, and that central command was unaware of the extent of the atrocities committed.

Koumjian, however, began by referencing historian Ben Kiernan in an effort to show that certain crimes against humanity were central policy and widespread across different regions.

Kiernan wrote that the central leadership issued commands to evacuate people from the cities, abolish currency and religion, execute leaders of the previous regime and expel ethnic Vietnamese from the country, among other crimes. “The same policies were carried out across Cambodia . . . in areas widely separated around the country,” Koumjian added.

Koumjian also tackled Guisse’s claim that the central leadership was simply unaware of the situation on the ground, referencing an interview with late King Father Norodom Sihanouk in which he recalls travelling the countryside with Khieu Samphan.

“I saw that the communes were concentration camps. I saw how the work went on day and night . . . sleep was not allowed,” Sihanouk said.

Koumjian also slammed the defence’s assertion on Wednesday that the massacres of urbanites or “new people” after their expulsion to the countryside were a result of pre-existing class tension. “They didn’t go there of their own choice,” Koumjian said, before pointing to a 1982 New York Times interview in which Samphan admitted to supporting the policy of forced relocation.

An edition of the central government’s propaganda magazine Revolutionary Flag, which was also referenced by Guisse on Wednesday, explicitly endorsed creating a hierarchy within cooperatives, ranking people as “full rights members, candidate members and depositees”, a reference to the displaced city dwellers.

Another recent point of contention has been the accusation that central party leadership exported rice to other countries while Cambodians starved to death in droves. On Wednesday, Guisse suggested it was possible zone leaders exported this rice without the knowledge of the two defendants.

But Koumjian yesterday read excerpts from speeches by both Samphan and his co-defendant Nuon Chea where they “bragged” about exporting rice. He then followed these speeches with telegrams from zone leader Ruos Nhim informing central leadership of widespread food shortages.

Stephen Heder, also quoted on Wednesday, claimed Khieu Samphan was responsible for the destruction of the National United Front of Cambodia (FUNC) and the Royal Government of the National Union of Kampuchea (GRUNK) and the deaths of some members. “Nine of the 16 people that Khieu Samphan had responsibility for in the FUNC and GRUNK governments were executed,” Koumjian said.

“These documents show not only Khieu Samphan’s knowledge of the killing campaign, but his active participation, facilitation and instigation of that campaign,” Koumjian concluded.

Guisse said that the defence was “not able to respond to the rebuttals of the co-prosecution today”, prompting judges to end the session early.