A court established by Russia-backed separatists who hold parts of eastern Ukraine has sentenced journalist Stanislav Aseyev, an RFE/RL contributor, to 15 years in a penal colony.
In a ruling condemned as "reprehensible" by RFE/RL's president, separatist news outlet DAN reported on Tuesday that the court had found Aseyev guilty of espionage, extremism, and public calls to violate the territory's integrity.
Aseyev, who wrote under the pen name Stanislav Vasin, disappeared in Ukraine's Donetsk region on June 2, 2017, and has been held in detention since by the separatists.
"The conviction against Stanislav Aseyev, which dates from August but was made public only today, is reprehensible," said RFE/RL President Jamie Fly.
"Stas is a journalist and was only trying to raise awareness about the situation in eastern Ukraine. The ruling is an attempt by Russian-backed separatists in Donetsk to silence his powerful, independent voice. Stas should be released immediately," Fly added.
The 30-year-old journalist was one of the few reporters in Donetsk who continued to work in the city after it came under the control of the separatists.
Representatives of the separatists accused Aseyev of observing the deployment sites of their paramilitary groups and passing on the information to the Ukrainian Security Service (SBU), according to the news outlet Hromadske.
In August 2018, the bipartisan U.S. Congressional Press Freedom Caucus called for Aseyev's immediate release, describing him as "one of the few independent journalists to remain in the region under separatist control to provide objective reporting."
U.S. Senator Marco Rubio (Republican-Florida) also called for Aseyev's release in July.
Media rights group Reporters Without Borders has also voiced concern about Aseyev's treatment, which it has called "increasingly disturbing."
RFE/RL has also urged the release of Ukrainian Service contributor Oleh Halaziuk, who has been held by Russia-backed separatists in Donetsk since August 2017.