Arseny Roginsky, a veteran activist who was chairman of the respected Memorial human rights society, has died after a life chronicling abuses and injustice in the Soviet Union and post-Soviet Russia.
Roginsky died on December 18 at the age of 71, Memorial said on its website.
The statement gave no cause of death. Media reports quoted friends and colleagues as saying that Roginsky died of cancer in Israel.
Born in 1946 in the northwestern region of Arkhangelsk, Roginsky was a Soviet dissident who got involved in human rights in the 1970s and worked, among other things, to expose the crimes of dictator Josef Stalin and his government.
In 1981, Soviet authorities arrested and sentenced him to four years in prison on a document-forgery charge after he rejected their order to emigrate.
"Many years before Memorial came into being, he began his struggle for historical truth and for human rights -- and was deprived of his freedom as a result," the Memorial statement said.
Roginsky was released in 1985, after serving his term, and was formally exonerated by Russian authorities in 1992 -- the year after the Soviet Union collapsed.
More recently, with President Vladimir Putin in power, Roginsky fought against what he once described as efforts by the authorities to push the memory of Stalin's abuses "to the distant periphery of the consciousness."
Roginsky co-founded the Memorial human rights society in 1988-89.
He served as chairman of the society, also known as the international branch of Memorial, from 1998 until his death.
"Thank you, Arseny Borisovich, you will always be with us," Memorial said in the statement on its website.
With reporting by Meduza and Moskovsky Komsomolets