Russian activist Ildar Dadin has been briefly detained while protesting in Moscow, two weeks after his release from prison.
Police detained Dadin on March 10 as he protested outside the Moscow headquarters of Russia's prisons service, according to his wife, Anastasia Zotova, and human rights defender Lev Ponomaryov.
They said Dadin and Ponomaryov were demanding the resignation of head of the prisons-service branch in the northwestern Karelia region, where Dadin says he was tortured last year.
Police said that they detained Dadin because he had no identity documents with him, and released him after Zotova brought his passport to the police station.
Ponomaryov said that police filed a report accusing Dadin of violating legislation on public gatherings.
Dadin was convicted and sentenced to prison in December 2015 under a controversial law that criminalizes participation in more than one unsanctioned protest in a 180-day period.
He was released on February 26 after the Supreme Court threw out his conviction and ordered the case closed.
Dadin, the only person in Russia who has been convicted under the law, was considered a political prisoner by major human rights groups.
Dadin's plight attracted additional attention last autumn, when he alleged he and other inmates had been tortured and abused at a prison in Karelia.