This archive report was first published on 7 September 2019.
On September 7, 2019, a historic prisoner exchange took place between Russia and Ukraine, marking the end of five years of bitter conflict.
Among the prisoners released were high-profile figures, including Ukrainian filmmaker Oleg Sentsov and journalist Roman Sushchenko.
Ukrainian filmmaker Oleg Sentsov, 43, was sentenced to 20 years in a Russian Arctic penal colony in 2015 on terror charges. His trial was likened to a Stalin-era show trial by Amnesty International.
Despite severe health problems and international pressure, including support from film stars like Johnny Depp, Sentsov remained unbroken, often smiling and singing the Ukrainian anthem during court appearances.
Another Ukrainian prisoner, Alexander Kolchenko, who was convicted as Sentsov's co-defendant with a lower sentence, was also released.
Additionally, Vladimir Tsemakh, an alleged air defence specialist for pro-Russian separatists who Dutch investigators have described as a key witness in the downing of flight MH17, was part of the exchange.
Journalist Kyrylo Vyshynsky, 52, who was detained in Kiev and charged with "high treason" in the interests of Moscow, was also released. He has dual Ukrainian and Russian citizenship.
Twenty-four Ukrainian sailors, including 22 sailors and two agents of Ukraine's SBU security service, were also released after being captured by Russian coastguards off the coast of Crimea in November last year.
Stanislav Klykh, 45, a history professor, and Mykola Karpyuk, 55, a senior member of two Ukrainian nationalist protest groups, were arrested in Moscow in 2014 and handed lengthy sentences for fighting against Russian armed forces in Chechnya in the 1990s.
They claimed to have confessed after being tortured.
Lastly, Pavlo Gryb, a 21-year-old blogger, was released after being sentenced to six years in prison for inciting a friend to carry out a bombing.
