Mam Nai or
Mam Nay,
nom de guerre Comrade
Chan is a war criminal and former lieutenant of
Santebal, the internal security branch of the
Khmer Rouge communist movement, which ruled
Democratic Kampuchea from 1975 to 1979. He was the leader of the interrogation unit at
Tuol Sleng (S-21), assisting
Kang Kek Iew (Comrade Duch), the head of the camp where thousands were held for
interrogation,
torture and subsequent killing.