The United Kingdom imposed sanctions on three Russian citizens on Friday in connection with the conviction of opposition activist and journalist Vladimir Kara-Murza (designated as a foreign agent in Russia), the British Foreign Office said in a statement.

The restrictions have been imposed on Andrei Zadachin, a high-profile case detective with the Russian Investigative Committee's Main Investigative Department who investigated the Kara-Murza case, Yelena Lenskaya, the judge who pronounced the sentence, and Denis Kolesnikov, the head of the Main Investigative Department.

The assets of those individuals will be frozen.

On Monday, the Moscow City Court sentenced Kara-Murza to 25 years' imprisonment at a high-security facility, a 400,000 ruble fine and a seven-year ban from engaging in journalistic activity.

The Russian citizen, who is also a British subject, was found guilty of treason, spreading disinformation about Russian military activities, and collaboration with an undesirable organization.

Kara-Murza denies all charges and says his prosecution is politically motivated. His defense team will appeal the conviction.