Russian prosecutors on Tuesday requested a 24-year sentence for respected former reporter Ivan Safronov, who is accused of treason for allegedly sharing state secrets.

The trial comes with independent media and NGOs facing increasing pressure in Russia, especially since the February start of Moscow's military intervention in Ukraine.

"The prosecutor asked to sentence Ivan to 24 years in a strict regime penal colony," Safronov's lawyer Dmitry Katchev told the RIA Novosti news agency following a closed-door hearing.

Safronov's former lawyer Yevgeny Smirnov said on Facebook that the ex-reporter turned down an offer of 12 years in jail in return for a guilty plea.

The 32-year-old worked for business newspapers Kommersant and Vedomosti and was one of Russia's most respected journalists covering defence.

He reported on the military, politics and Russia's space programme.

Safronov was arrested in July 2020, after leaving journalism to serve as an adviser to the head of the state space agency.

The FSB security service has accused Safronov of collecting confidential information about Russian military, defence and security and handing it over to the intelligence service of a NATO member country.

Safronov appeared in court Tuesday inside a glass cage for defendants, wearing a black T-shirt with the Star Wars logo, according to images released by the court.

The verdict in his case will be announced on September 5, Russian news agencies said.

At the start of his trial in April, Safronov called the case a "complete travesty of justice" and said he was not guilty.

The ex-journalist has said his reporting was based on analysis of open sources and conversations with officials, adding that he had not been told what constituted treason in his case.

Safronov's case triggered a backlash from independent journalists and -- in an unusual move -- from several reporters in the Kremlin press pool covering President Vladimir Putin.

The Kremlin insisted Safronov's detention was not related to his previous work as a journalist.

Former Roscosmos chief Dmitry Rogozin has said that Safronov did not have access to secret information during his time at the space agency.

According to Safronov's lawyers, it was the first time in nearly two decades that a journalist has been arrested and placed in pre-trial detention on treason charges.

A growing number of Russians in other professions have in recent years been accused of high treason or disclosing state secrets.

The start of Moscow's military campaign in Ukraine has also seen an intensified crackdown on independent media outlets -- many of which shut down -- and journalists.

Over the weekend, Moscow police detained journalist and plagiarism campaigner Andrey Zayakin, who is accused of financing "extremist activity".

The charges concern a 1,000-ruble ($16) donation to an organisation of jailed Kremlin critic Alexei Navalny that was labelled "extremist" last year.

The journalist works for prominent newspaper Novaya Gazeta, whose editor-in-chief last year won the Nobel Peace Prize.

He also co-founded an online platform that uncovers plagiarism or falsehoods in PhD works and scientific articles, including among officials.

A Moscow court banned Zayakin from using the internet and restricted his movements as part of pre-trial measures.

If found guilty, he faces up to eight years in prison.