Ukraine on Wednesday released a Russian state media journalist pending his trial for "high treason", as the two countries discuss potential prisoner swaps.
Kyrylo Vyshynsky, a journalist at Russia's RIA Novosti news agency, was released on condition he not leave the country and appear for his trial, his lawyer Andrii Domansky told AFP.
Ukraine's SBU security service raided the Kiev offices of RIA Novosti last year, saying the agency and its journalists had been "used as tools in a hybrid war against Ukraine".
Vyshynsky, a Ukrainian national who received a Russian passport in 2015, was detained the same day near his house in Kiev and accused of high treason.
The SBU accused Vyshynsky of travelling to Crimea in 2014 to carry out "subversive" reporting to justify the peninsula's annexation by Russia.
The 52-year-old was also accused of collaborating with Russia-backed separatist groups in eastern Ukraine.
His release on bail comes amid reports that Moscow and Kiev have been preparing for prisoner exchanges as part of increased efforts to resolve their longstanding conflict.
The election this year of President Volodymyr Zelensky has given fresh life to peace efforts, with the leaders of Russia, Ukraine, Germany and France set to meet next month for a summit.
Some 13,000 people have been killed in the conflict with Russia-backed separatists since Moscow annexed Crimea in 2014, a move the international community refuses to recognise.
Zelensky, a comedian-turned-politician who swept to power on promises of change, has signalled he is ready for talks with Russia on resolving the conflict.
Zelensky in July offered to hand Vyshynsky over to Moscow in exchange for Ukrainian film director Oleg Sentsov, who is behind bars in a Russian Arctic penal colony.
Sentsov, Ukraine's most famous political prisoner, is serving a 20-year sentence in a Russian penal colony for planning "terrorist attacks" in Crimea.
A prisoner exchange would be a key first step in reducing tensions between Kiev and Moscow.
Among other individuals that could be involved in an exchange are 24 Ukrainian sailors captured last year.
Russia has been holding the sailors since their three vessels were seized off Crimea last November, in the most dangerous direct clash between Russia and Ukraine in years.
French President Emmanuel Macron announced next month's summit at the weekend, saying the conditions were right for "useful" talks.
It would be the first summit between the leaders of the four countries -- the so-called Normandy format -- since 2015.