A member of the protest group Pussy Riot has been detained by the police anti-extremism division, the Russian state news agency Tass has said.
Pyotr Verzilov was seized at his apartment by unidentified men who broke down the door on Sunday morning, the Mediazona website – which Mr Verzilov publishes – reported.
Tass cited a police source saying Mr Verzilov was detained as part of an investigation but did not report further details.
Mr Verzilov attracted worldwide attention in 2018 when he and three other Pussy Riot activists ran onto the field of the World Cup final in Moscow to protest police brutality, an action for which they served 15 days in jail.
Two months later, he became severely ill from what group members suspected was poisoning and was flown to Germany for treatment.