Two of them were released after a police interrogation, Baza said.

Baza – which means “Base” – specialises in criminal news and investigations. It has more than 1.5 million subscribers on Telegram and is known to have good sources within law enforcement agencies.

Police seized documentation and computers from the outlet’s Moscow office and raided editor-in-chief Gleb Trifonov’s flat, his lawyer Alexey Michalchik told Baza.

Trifonov was being questioned by police without a lawyer, the outlet added.

Police spokesman Irina Volk said that the force had detained some officers who “passed on information obtained over the course of their duty to third parties”.

Russia’s investigative committee posted on Telegram saying that it had “initiated a criminal case on abuse of authority by police officers”.

It said that raids were conducted in Moscow and in several other regions, without specifying if these were related to the Baza probe.

Members of the police force are suspected of leaking classified information that later appeared “on a Telegram channel”, investigators said without naming Baza.

Moscow has escalated its decade-long crackdown on independent media amid its military offensive in Ukraine by passing sweeping censorship laws, effectively banning any criticism of the military.