"As a result of joint efforts by the investigators of the Main Investigative Directorate of the Russian Federation and the FSB Security Service of Russia, a Ukrainian citizen Roman Ternovskiy was detained, who was affiliated with the Right Sector extremist organization, banned by the Supreme Court of the Russian Federation," the report says.

It is claimed that Ternovskiy, as a member of the Right Sector organization, repeatedly took part in pickets, rallies, and other public events in the territory of Ukraine. Also, using his Facebook profile, Ternovskiy promoted the Right Sector organization among netizens, including those living in Russia.

Read alsoJournalists find out how FSB lured Ukrainian youngster to Belarus for abduction"Ternovskiy's actions are aimed against the interests of the Russian Federation and qualified by the investigation under Part 2 Article 2822 of the Criminal Code, which provides for criminal liability for participation in an extremist organization," the report reads.

During the search in Ternovskyi's place of residence in Rostov-on-Don, the operatives have reportedly discovered clothes and other items with Right Sector insignia and prints.

The court has taken Ternovsky into custody at the request of the investigators.