The New York-based Students for a Free Tibet said Tenzin Delek Rinpoche's body was cremated Thursday in a secret prison near the one in Chengdu city in southwest China where he had been held for the last 13 years.
Local police and prison authorities, contacted by phone, said they didn't know about the case.
Tenzin Delek died on Sunday while serving a life sentence on charges of financing and supporting a series of terrorist bombings and secession activities. His supporters say the charges were trumped up.
