A Russian journalist has been convicted of treason and handed a 22-year prison sentence after a trial that has been widely seen as politically motivated and marked a new step in a sweeping crackdown on the media and Kremlin critics.

The sentence handed to Ivan Safronov, who worked as a military affairs reporter for leading business daily Kommersant before becoming an adviser to the head of the Russian space corporation Roscosmos, was criticized by his colleagues as utterly unfounded.

A few friends and co-workers of Mr. Safronov who attended Monday’s hearing at the Moscow City Court chanted “Freedom” and clapped after the verdict was read.

“I love you all,” Mr. Safronov told those who came to support him.

Mr. Safronov was accused of passing military secrets to Czech intelligence and a German national. He insisted on his innocence, arguing that he collected all the information from open sources as part of his journalistic work and did nothing illegal.

Separately on Monday, a Moscow court revoked the print license of independent newspaper Novaya Gazeta, whose chief editor, Dmitry Muratov, was co-awarded the Nobel Peace Prize last year. The Moscow Times reported that Russia’s media watchdog, Roskomnadzor, maintained that Novaya Gazeta failed to provide its editorial statute within a required timeframe.

Mr. Muratov slammed the court’s decision as politically motivated, and in an official statement following the court ruling said, “The newspaper was killed today.”

While the newpaper suspended its print publication in March, following the Kremlin’s clampdown on media following the invasion of Ukraine, as of September 6 its website was still live and carried news about the Soviet Union’s last leader, Mikhail Gorbachev. The Moscow Times reported that Gorbachev had donated a portion of his 1990 Nobel Peace Prize money to establish Novaya Gazeta.

The newspaper’s online version also carried news of the sentencing of Mr. Safronov. The AP reported that in his final statement at the trial last week, Mr. Safronov rejected the charges of treason as “absurd,” noting that he published all the information he gathered from his sources in government agencies and military industries.

He emphasized that he never had access to any classified documents and emphasized that investigators have failed to produce any witness testimony to back the espionage charges.

Mr. Safronov described the long sentence requested by prosecutors as “monstrous,” saying that it would stain the country’s image by showing that a journalist is sentenced simply for doing his job. His defense quickly appealed the sentence.

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

Hours before the ruling was announced by the Moscow City Court, 15 independent Russian media outlets issued a joint statement demanding Mr. Safronov’s release.

“It is obvious to us that the reason for persecuting Ivan Safronov is not ‘treason,’ which hasn’t been substantiated … but his work as a journalist and stories he published without any regard for what the Defense Ministry or Russian authorities think,” the statement read.

The European Union on Monday urged Russian authorities to drop all charges against Mr. Safronov and “release him without any conditions,” denouncing “systematic repressions of the regime against independent journalism.”

The Kremlin has remained unperturbed, with President Putin’s spokesman, Dmitry Peskov, refusing to comment on the case in a conference call with reporters.

Mr. Safronov has been in custody since his July 2020 arrest at Moscow.

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.

Mr. 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.