Vysotsky, a Ukrainian citizen, had been convicted of high treason and espionage for an unidentified foreign state and sentenced to 12 years in prison.
The Ukrainian government had included him on a list of people potentially to be exchanged for Ukrainian nationals held in Russia.
On June 6, Zelenskiy's representative to the contact group on regulating the war in parts of eastern Ukraine, former President Leonid Kuchma, said the issue of a prisoner exchange with Russia had been discussed.
"Both sides need to take initial steps," Kuchma said.
Radio Liberty
