As reported by Censor.NET citing Ukrinform, this is stated in a European Parliament resolution "On Russia, notably the case of Ukrainian political prisoner Oleh Sentsov," which was adopted on Thursday.
"The European Parliament demands that the Russian authorities immediately and unconditionally release Oleh Sentsov and all other illegally detained Ukrainian citizens in Russia and on the Crimean peninsula," the document reads.
The resolution mentions the names of more than 70 Ukrainian political prisoners held in Russia and in occupied Crimea, including Ukrinform journalist Roman Sushchenko.
MEPs also expressed their solidarity with Ukrainian filmmaker, political activist and political prisoner Oleh Sentsov, who went on a hunger strike on May 14, 2018 to press for the release of illegally detained compatriots.
The resolution notes that another illegally detained Ukrainian citizen, Volodymyr Balukh, is on hunger strike since March 19.
MEPs expressed their deep concern that many of the Ukrainian political prisoners, such as Mykola Karpiuk, Volodymyr, Prysych, Oleksiy Chirniy and Yevhen Panov, had been seriously tortured.
The European Parliament also draws attention to the detention of Crimean Tatars by the Russian authorities in occupied Crimea.
"The European Parliament condemns Russia's violations of international law in occupied Crimea, including the enforcement of Russian legislation, the heavy militarization of the Crimean peninsula, which threatens the regional security, and the massive and systematic human rights violations targeting, in particular, ethnic Ukrainians and Crimean Tatars," the resolution says.
The European Parliament called on the European Union's Special Representative for Human Rights to pay continuous attention to the human rights situation on the Crimean peninsula and in the non-government controlled areas of eastern Ukraine.
As reported, Sentsov is serving a sentence in the maximum security labor camp in the Yamalo-Nenets Autonomous District. This prison's inmates are serving sentences for commission of grave and especially grave crimes.
Sentsov was detained by the Russian FSB Security Service in Russian-occupied Crimea in 2014 together with activist Oleksandr Kolchenko. They were brought to Russia and tried in a trumped-up case on charges of organizing acts of terror and arson on the peninsula. On Aug. 25, 2015, Sentsov and Kolchenko were sentenced to 20 years' and 10 years' in prison, respectively. On Oct. 21, 2016, Russia refused to extradite the two Ukrainians to Ukraine, claiming they had automatically acquired Russian citizenship after the annexation of Crimea.
Sentsov’s sister Natalia Kaplan said March 16, 2018 that her brother reported on his failing health in a letter. He in particular said that he is losing his hair and has his teeth crumbling into small pieces.
On May 14, 2018, the fillmmaker said he went on an indefinite hunger strike demanding to release all Ukrainian political prisoners held in Russia.