MOSCOW, April 9 (Reuters) - Security officers raided the Moscow office of leading independent Russian newspaper Novaya Gazeta on Thursday and state media said a prominent journalist had ‌been arrested.

State news agency RIA quoted law enforcement authorities as saying the reporter, ‌Oleg Roldugin, was being questioned over alleged misuse of personal data.

It published a brief video showing a man being frogmarched ​to a van by several masked security officers and bundled inside.

Russia has tightened its censorship laws and increased pressure on independent media since it launched its war in Ukraine in 2022.

In a separate development, Russia's FSB security service said on Thursday it had detained a former Radio Free Europe ‌freelance journalist on suspicion of ⁠treason for passing information to Ukrainian intelligence.

In a further move to clamp down on dissent, Russia's Supreme Court ruled on the same day that leading ⁠human rights group Memorial was an extremist movement, paving the way for the prosecution of anyone who supports it, donates to it or shares its materials.

PAPER'S EDITOR WON NOBEL PEACE PRIZE

Roldugin, the arrested journalist, ​previously ​ran a weekly newspaper called Sobesednik whose publisher was ​labelled a "foreign agent" months after it ‌published a front-page story in 2024 on the death in a penal colony of leading dissident Alexei Navalny. Later that year, it was forced to suspend publication.

The journalist recently published an article in Novaya Gazeta investigating how a former aide to the nephew of Chechen leader Ramzan Kadyrov was able to acquire one of Russia's most expensive penthouses.

Novaya Gazeta said Roldugin was taken ‌in for questioning after a search of his flat ​on Thursday morning. The newspaper added that it could ​not confirm whether searches at its office ​were linked to his case.

Novaya Gazeta is one of Russia's best-known investigative ‌news outlets. Its editor-in-chief Dmitry Muratov was ​co-winner of the 2021 ​Nobel Peace Prize, and dedicated the award to six of his paper's journalists who were murdered for their work.

Muratov was designated in 2023 as a "foreign agent", a label that ​the authorities apply to individuals ‌and organisations they deem to be conducting anti-Russian activity with support from abroad.

He was ​not available for comment on Thursday's raid on the paper.

(Reporting by Reuters, writing ​by Mark Trevelyan in London,Editing by Keith Weir)