A man named Evgeny Petrin working in the Moscow Patriarchate’s office has been arrested on suspicion of treason, accused of passing classified intelligence to the United States. A Moscow court official told reporters that Russia’s Federal Security Service (FSB) is handling Petrin’s case.

According to the news agency LifeNews, Petrin worked for the Moscow Patriarchate’s Department for External Church Relations, where his job entailed regular communication with foreigners. Petrin is accused of visiting individuals suspected of spying for the US, and passing along information about the Church’s activities, in order to gain their trust. Petrin says he only ever shared publicly available information.

Journalist Olga Romanova says Petrin wrote her a letter from jail, where he allegedly claimed to hold a major’s rank in the FSB. He says the FSB sent him to serve in the Orthodox Church, then sent him to Ukraine, and finally they recalled him to Moscow, where he was arrested. In his letter, Petrin calls his detention illegal, and says he used to report information to the FSB about foreign agents “active in the administration of the Church and the state.”

Moskovsky Komsomolets reporter Eva Merkacheva says she met with Petrin in jail. She calls him a captain in the FSB, confirming that he was sent to Ukraine in the Russian Orthodox Church’s official delegation. Merkacheva says Petrin only confessed to treason after being severely beaten while in police custody.

Of Russia’s recent treason cases, the prosecution of Svetlana Davydova, a mother of seven children, has resonated most strongly with the public. Investigators say Davydova handed over classified information about Russian troop movements to the Ukrainian embassy. Following a campaign to free her from jail, police later released Davydova on her own recognizance.

Vladimir Golubev, a former researcher at the Russian Federal Nuclear Center, also stands accused of treason. The FSB says he disclosed state secrets when he published an article about explosives in a Czech scientific journal in 2013. Golubev denies these accusations.