Until a couple of months ago, Oleg Sentsov was serving a 20-year jail term in Russia.

But today the Ukrainian filmmaker was being lauded in front of MEPs as he picked up the European Parliament's freedom of thought award.

Sentsov, 43, was arrested during a 2014 protest over Russia's annexation of Crimea. He was given a 20-year sentence for terrorism.

It was denounced by the United States and the European Union, but Russia denied he was a political prisoner.

The 43-year-old was released in September 2019 as part of a prisoner swap between Moscow and Kyiv.

"While we are talking here in Strasbourg, in warmth and safety, our guys are still there, in Russia," Sentsov told Euronews after receiving the parliament's Sakharov Prize on Tuesday, which he was awarded while still behind bars.

"They are experiencing, perhaps even great suffering, about which we know nothing.

"More than a hundred people in Russian prisons and more than two hundred in Donbas prisons of separatists."

The five-year conflict in east Ukraine between pro-Russian separatists and Ukrainian government forces has seen 13,000 people killed.

But while the election of Ukraine President Volodymyr Zelenskiy and the subsequent prisoner swap can count as progress, there remains a lot of mistrust between both sides.

Sentsov claims Russian President Vladimir Putin is feeling the pressure at home.

"Gradually, the Russian people are getting tired of all these supposedly political gains, which are PRed (promoted) by propaganda," he said.

"Because over the five years their lives were getting worse, and on TV they are told that they live better. Accordingly, people stop believing in it. Over the five years that I spent in Russia, they are being told only about Ukraine."

Undoubtedly it was outside political pressure that brought about Sentsov’s release — but for the moment — it seems no level of political pressure or indeed awards in Strasbourg are likely to change the reality of the frozen battles lines in eastern Ukraine.

That, however, could change on December 9, when the leaders of France, Germany, Russia and Ukraine meet in Paris for peace talks.

The Sakharov Prize is given to those who have dedicated their lives to the defence of human rights and freedom of thought.