Russian authorities in annexed Crimea detained on Thursday a Tatar lawyer for allegedly spreading "extremist propaganda", activists said, the latest step in an official crackdown on the pro-Ukraine Muslim community.

Emil Kurbedinov was detained as he headed to a client's house that was being raided by law enforcement agents over purported ties to the banned Islamist group Hizb-ut-Tahrir.

"They are accusing him of spreading extremist propaganda," Crimean Tatar activist Abdureshit Dzhepparov said.

Officials in Crimea have cracked down on the region's Tatar population, who were deported by Stalin and largely opposed Moscow's 2014 takeover of the strategic Black Sea peninsula, banning their governing body and closing independent media.

Authorities have used claims of membership of Hizb-ut-Tahrir to raid homes and arrest a string of Tatars, but activists have decried the allegations as a cover for targeting their community.

The fall of Crimea into the hands of Putin's Russia in 2014 was a frightening reality for Crimean Tatars, as it would signal an end to the freedom they enjoyed within Ukrainian territory with regard to Russian provocations against the Crimean Tatar minority in the annexed territory.

Russians are the vast majority in Crimea, with 5 million ethnic Russians residing in the Ukrainian part of Novorossiya. The mass deportation of Crimean Tatars in 1944 also led many to fear Russian policies.