MOSCOW -- Well-known Soviet-era dissident and human rights activist Valery Senderov has died at the age of 69.
Senderov's friends say he unexpectedly died in his Moscow apartment on November 12. It is unclear what caused the death.
In 2012, Senderov was diagnosed with Parkinson's disease.
Senderov, a mathematician and philosopher, began his human rights activities in the late 1970s. He was arrested in 1982 and sentenced to seven years in jail and five years of exile for "anti-Soviet propaganda."
Senderov, along with many other dissidents, was released from jail in March 1987 amid Soviet leader Mikhail Gorbachev's perestroika policies.
After his release, Senderov actively participated in the creation of the Christian-Democratic movement in Russia.
With reporting by grani.ru