Ukraine's intelligence service says its officers have searched the home of the father superior of Kyiv's biggest and oldest monastery, which is affiliated with the Russian Orthodox Church.
Ihor Huskov, chief of staff of the SBU intelligence agency, told reporters on November 30 that Metropolitan Pavlo, who oversees the Kyiv-Pechersk Lavra monastery, was suspected of "inciting hatred."
The SBU was investigating him under an article in the Criminal Code covering "violations of citizens' equality depending on racial ethnicity, religious convictions, incitement of interconfessional hostility," Huskov said.
Metropolitan Pavlo confirmed the raid.
"Today there are many questions about whether the actions of our state authority in relation to the church are legitimate. To a certain extent they are illegal," Pavlo said in a statement.
"There is a pressure on me personally, threats are being heard, all sorts of attacks not only on me, but also on other bishops and priests. For what reason I do not know."
The Kyiv-Pechersk Lavra, or Monastery of the Caves, is one of Ukraine's most famous monasteries and a tourist site where mummified monks rest in labyrinthine underground caves.
The raid came a day after President Petro Poroshenko announced Ukraine was close to setting up an independent church under a charter from the Ecumenical Patriarch in Istanbul, the global spiritual head of Orthodox Christians.
There are currently three Orthodox communities in Ukraine, including two breakaway churches.
The Ukrainian church, which has been part of the Russian Orthodox Church for centuries, moved close to forming an independent church earlier this year.
The Ukrainian Orthodox Church of the Kyiv Patriarchate broke away from Moscow in 1992 after the fall of the Soviet Union.
Its bid for recognition as a self-governing or autocephalous institution intensified after Russia's 2014 annexation of the Crimean Peninsula from Ukraine and its support for separatists in eastern Ukraine.
Tensions between Ukraine and Russia have escalated since last weekend, when Russian border guards opened fire on three Ukrainian naval vessels near Crimea and captured their crews.