The Khmer Rouge's main jail chief on Thursday told the UN-backed war crimes tribunal that he adopted "Duch" as his revolutionary name because it was Cambodian and his real name was not.
Duch, whose real name is Kaing Guek Eav, is on trial in Cambodia for overseeing the torture and execution of about 15,000 people at Tuol Sleng detention centre in the late 1970s.
The former prison chief said he changed his name to Duch in 1967.
"I wanted a name in Khmer (the Cambodian language), not a kind of Chinese one," Duch said.
He added he also chose the revolutionary name because it was one used by a good student in a book he studied when he was young.
"So Duch is a good one and has Khmer character. That's why I used Duch," said the former maths teacher.
Duch has repeatedly accepted responsibility for his role in governing the jail under the regime and begged for forgiveness from the families of the victims.
Led by Pol Pot, who died in 1998, the Khmer Rouge emptied Cambodia's cities in a bid to forge an agrarian utopia, resulting in the deaths of up to two million people from starvation, overwork and torture.