Ukrainian political prisoner Stanyslav Klykh in the Russian Federation has been sent to serve out his prison sentence in a prison located in Chelyabinsk, his lawyer Ilya Novikov has said. Klykh had been held in Grozny, Russia.

"They took [him from Grozny] on January 7. We learned this yesterday, on Monday," Novikov said in an interview aired on the Ukrainian 112 TV channel on Tuesday.

According to Klykh's lawyer over the next three weeks "we will not hear anything new about him." Klykh's whereabout remain unknown.

"Unfortunately, this is completely lawful, according to the Russian Federation's penal system. It reports that a prisoner has been moved and informs about the destination post-factum," Novikov said.

Novikov said Ukrainian citizen Volodymyr Karpiuk, also a political prisoner, was moved from Grozny via the Russian city of Izhevsk.

The lawyer said that he believes the only way to free Klykh in the near future would be through a prisoner exchange between Russia and Ukraine arranged by the countries' politicians.

As earlier reported, the Supreme Court of Russia's Chechnya region on May 26, 2016 sentenced Karpiuk and Klykh to 22.5 and 20 years in prison, respectively, for allegedly taking part in fighting with Russian army forces during the first Chechnya war during the early 2000s. Both men deny the charges.