MOSCOW (AP) — Doctors say a hospitalized member of protest group Pussy Riot may have been poisoned by an overdose of medication.

Independent news website Meduza reported Thursday that Pyotr Verzilov's doctors told his relatives that he either overdosed on medicine or was given too much medicine. The report did not specify the substance.

Fellow Pussy Riot member Veronika Nikulshina told The Associated Press that the report was accurate but wouldn't comment further.

Friends insisted that Verzilov hadn't been taking medications or using drugs. Verzilov has been hospitalized in Moscow since Tuesday.

Verzilov and other activists served 15-day jail sentences for disrupting July's World Cup final to protest excessive Russian police powers.

Speaking to The AP last week, Verzilov said, "Public protest in Russia is the only way to actually change anything."