Yuri Orlov, a Soviet physicist and disillusioned former Communist who publicly held Moscow accountable for failing to protect the rights of dissidents and was imprisoned and exiled for his own apostasy, died Sept. 27 at his home in Ithaca, NY. He was 96.

Professor Orlov was released from Siberia in 1986 in a prisoner exchange before his 12-year term in a labor camp and exile expired. He was banished from the Soviet Union and went to the U.S., where he pursued scientific research and human rights advocacy. Beginning in 1987, he taught physics and government at Cornell University in Ithaca. He became a citizen in 1993.

He helped organize the Soviet branch of Amnesty International and, in 1976, founded what was considered his most enduring legacy: the Moscow Helsinki Group, which monitored Soviet compliance with the human rights commitments that had been outlined in the 1975 Helsinki Accords, signed by some 35 nations.

Natan Sharansky, another Soviet physicist and a Jewish “refusenik” who was arrested in the late 1970s and imprisoned for protesting the government’s refusal to grant him a visa to travel to Israel, recalled that what Professor Orlov proposed was “unprecedented in its boldness…it was Orlov’s bold vision that made our efforts so effective,” he said.