MOSCOW (AP) — The trial of a former journalist who has remained behind bars for more than 20 months on charges of passing military secrets to Czech intelligence began in a Moscow court on Monday.

Ivan Safronov has vociferously insisted on his innocence, while he and many of his colleagues have dismissed the charges as absurd.

Safronov had written about military and security issues for a decade before becoming an adviser to Dmitry Rogozin, the head of the Russian space agency Roscosmos. He as remained in custody since his July 2020 arrest in Moscow by agents of the Federal Security Service (FSB), the main successor to the KGB.

Speaking to reporters from a glass cage at the Moscow City Court before the start of the closed doors proceedings, Safronov rejected the charges as “nonsense." He faces up to 20 years in prison if convicted.

In a speech released by his lawyer prior to the trial's start, Safronov said he had collected all the information from open sources in the course of his work and did nothing illegal. He argued that the FSB has failed to clearly outline 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.

The FSB has accused Safronov of relaying sensitive data to a spy agency of an unspecified NATO member that related to "military-technical cooperation, defense and security of the Russian Federation.” Safronov’s lawyers have specified that the FSB has accused Safronov of cooperating with an intelligence agency in the Czech Republic, providing information about Russian arms sales to the Middle East and Africa when he worked as a correspondent for top Russian business daily Kommersant.

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.