Russia’s Foreign Ministry said Tuesday it had summoned a senior Czech diplomat to demand the release of a Russian Orthodox cleric who was detained after containers of a suspicious white substance were found in his car.

Metropolitan Hilarion, born Grigory Alfeyev, was detained on Sunday after Czech police found four containers of a “white substance” in the trunk of his car, according to his Telegram channel. Hilarion denied allegations of drug possession.

In its statement, Russia’s Foreign Ministry said it had summoned the Chargé d'Affaires of the Czech Republic in the Russian Federation, Jan Ondřejka, to protest Hilarion’s detention pending forensic chemical results to determine if formal charges will be filed.

“The ministry pointed out the sheer absurdity and total lack of foundation regarding the accusations,” it said.

Czech police confirmed they detained an individual on Sunday evening along a highway between the spa town of Karlovy Vary and Prague. They said “no one has been charged yet” but did not disclose the person’s identity.