A reference by the Federal Penitentiary Service of Russia handed to the Ukrainian Consulate in Yekaterinburg certifies that the Russian side recognizes Oleh Sentsov a citizen of Ukraine, the filmmaker's lawyer, Dmitry Dinze, says.

This refutes the assertion of the Russian side that Sentsov at the time of his conviction was a citizen of the Russian Federation, according to Ukrayinska Pravda.

"Convict Sentsov O.G. is a citizen of the Republic of Ukraine and  was transferred October 9, 2017. In his case file, there is passport EC 477125, issued on November 12, 1997," the reference says.

Read alsoHunger-striking Sentsov's health "very weak" - lawyer

UNIAN memo. Sentsov was detained by FSB operatives in Crimea in the spring of 2014. He was transferred to Russia, where he was tried on trumped-up charges of plotting terrorist attacks and arson of party offices on the peninsula.

The Russian court in August 2015 sentenced Sentsov to 20 years in prison.

He is being held in the colony located in a distant town of Labytnangi in Yamalo-Nenets Autonomous Area, Russia.

On May 14, Sentsov went on a hunger strike demanding the release of all Ukrainian political prisoners. 

On June 15, Ukrainian Ombudsperson Liudmyla Denisova was denied access to Sentsov.