MOSCOW (AP) — Russian prosecutors at the trial of a former journalist asked the court Tuesday to hand him a 24-year prison sentence on treason charges.

Ivan Safronov. who worked as a journalist for a decade before becoming an adviser to the head of the Russian space corporation Roscosmos, has been in custody since his July 2020 arrest in Moscow. He has rejected the charges of passing military secrets to Czech intelligence and insisted on his innocence.

Safronov's case reflects the challenges faced by Russian journalists, which have grown even tougher amid Moscow's military action in Ukraine.

Safronov, who covered military and security issues for the leading Russian business daily Kommersant before joining Roscosmos, stated that he had collected all the information from open sources in the course of his work and did nothing illegal. He has argued that the investigators have failed to spell out the treason charges and explain what secrets he had allegedly revealed.

Many Russian journalists and human rights activists have pushed for Safronov’s release, and some have alleged that the authorities may have wanted to take revenge for his reporting that exposed Russian military incidents and shady arms deals.

Roscosmos has said that Safronov didn’t have access to state secrets, and claimed that the charges didn’t relate to Safronov’s work for the corporation, which he joined in May 2020.

Rights activists, journalists, scientists and corporate officials who have faced treason accusations in Russia in recent years have found it difficult to defend themselves because of secrecy surrounding their cases and a lack of public access to information.

Safronov’s father also worked for Kommersant covering military issues after retiring from the armed forces. In 2007, he died after falling from a window of his apartment building in Moscow.

Investigators concluded that he killed himself, but some Russian media outlets questioned the official version, pointing to his intent to publish a sensitive report about secret arms deliveries to Iran and Syria.