Cambodia’s UN-backed Khmer Rouge tribunal on Thursday rejected the appeal of a genocide conviction by the communist group’s last surviving leader in what is expected to be the special court’s last session.

The historic international court issued its ruling on an appeal by Khieu Samphan, who served as head of state in Cambodia’s 1975-79 Khmer Rouge government. He was convicted in 2018 of genocide, crimes against humanity and war crimes and sentenced to life in prison.