The Khmer Rouge's chief torturer and jailer has expressed "excruciating remorse" for more than 14,000 people killed under his watch, Sky News reported.
Kaing Guek Eav, better known as Duch, was in charge at a notorious prison during Cambodia's ultra-Maoist revolution of the 1970s.
The 67-year-old former math teacher admits being liable for the killings but insists he was serving a mafia-type group "I could not withdraw from," Sky News reported.
He is accused at a U.N.-backed 'Killing Fields' tribunal of "crimes against humanity, enslavement, torture, sexual abuses and other inhumane acts" as commander of S-21 jail.
Witnesses have told of beatings with metal pipes, electrocution, near-starvation, violent rape and forcing some prisoners to eat their own excrement, Sky News reported.
Duch denies personally murdering or torturing prisoners and insists he was following orders out of fear for his own life.