Over the weekend, two members of the Pussy Riot collective who stormed the field at this year’s World Cup—Veronika Nikulshina and Peter Verzilov—were arrested in Moscow during a day of widespread protests in Russia. It’s now been revealed in the Russian publication Meduza that Verzilov was hospitalized yesterday (September 11) and was in serious condition following a possible poisoning. According to a subsequent report from Meduza, doctors believe Verzilov “overdosed on or was poisoned by anticholinergic drugs.” His family reportedly told the publication “they are ‘1,000-percent’ certain that he didn’t willingly ingest any anticholinergic drugs.”

Nikulshina said that after a court session, Verzilov began to lose his sight, speech, motor skills, and memory. Verzilov was reportedly taken to a toxicological department, and doctors would not tell Nikulshina whether or not Verzilov was poisoned. “The doctor only said that his condition was serious, but his behavior was improving and he’d started responding to his own name,” Nikulshina said.

UPDATE (09/14 6:50 p.m. ET): Verzilov has regained consciousness after being hospitalized for three days, Meduza reports. According to Veronika Nikulshina, Verzilov's common-law wife, he is still experiencing “hallucinations” and remains in a “delusional state.”

In a new statement, Pussy Riot addresses the possibility that Verzilov had been poisoned. “Doctors refuse to share with us any papers on Peter’s health. We have all the reasons to suspect that he was poisoned by the Russian authorities,” they write. “We demand justice, and we’ll do everything we could to find those people who’re in charge of poisoning Peter and be sure that they will be punished for what they did.”

This article was originally published on Wednesday, September 12 at 5:47 p.m. Eastern. It was last updated on September 15 at 12:15 a.m. Eastern.