The office of the commissioner is now working to facilitate extradition of another group of convicts, Ukrainian citizens, who expressed their will to serve the rest of their sentences in mainland Ukraine, according to Krym-Realii.

Read alsoMogherini in Moscow: EU does not recognize Crimea annexation"Yesterday, we sent an appeal to the Russian ombudswoman in order to settle this issue [with Andriy Lugin's extradittion] and begin the next stage of the negotiations on how to repeat the procedure already carried out with regard to 12 other prisoners, who we've managed to transfer to the Kyiv-controlled territory," Chaplyga said.

A citizen of Ukraine, ex-deputy of the Kerch City Council Andriy Lugin, who has been kept in custody in the Simferopol pre-trial detention facility, declared a dry hunger strike on Monday, April 24. He was convicted by the Court of Appeals in Crimea in 2010. The man claims Russian-backed officials in Crimea have been violating his rights over the past three years.