Once considered a possible successor to Patriarch Kirill, Metropolitan Hilarion fell from grace amid sexual misconduct allegations. Now he’s embroiled in a drug scandal in the Czech Republic.

Metropolitan Hilarion, a Russian Orthodox Church priest based in the Czech Republic, spent two days in police custody. On May 24, his car was stopped on the basis of an anonymous tip and the trunk was searched. Officers found “four small containers with a white substance” that turned out to be an illicit drug. Hilarion insisted he had no idea how the substance ended up in his car. On May 26, he was released without charges. But the incident was unprecedented for the Russian Orthodox Church, whos...