Putin purged large numbers of FSB agents in retribution for poor Ukraine intelligence, Russia expert says

• Putin has 'purged' a key unit of his secret service over Ukraine intelligence failures, per Bellingcat.
• Bellingcat's Russia lead confirmed the arrest of Fifth Service head Sergio Beseda in an interview.

Large numbers of officers in Russia's secret service have been "purged" in the wake of the country's military failures in Ukraine, a top investigative journalist said.

Christo Grozev, the lead Russia journalist for investigative outlet Bellingcat, spoke in an interview about officers in the Fifth Service, the branch of security agency FSB that is concerned with former Soviet territories such as Ukraine.

YouTube channel Popular Politics conducted the interview in Russian and published it on Monday.

Grozev said that many of the unit's roughly 150 officers have been arrested or "certainly no longer work for the FSB," Grozev said.

The head of the Fifth Service, Sergio Beseda, was put under house arrest in early March, according to Russia expert Andrei Soldatov, something that the Kremlin has not officially confirmed.

Beseda has since been transported to Lefortovo Prison, according to Soldatov. It has a brutal reputation as the site of interrogation and torture during the Stalinist purges.

Grozev said that the news of Beseda's arrest had been covered up in Russian media. He said that compliant outlets reported the "leak" was false, and had been planted in order to identify a leaker.

This would appear to concur with earlier suggestions that Putin was combing the unit for moles.

However, the arrest indeed took place, Grozev said, without naming sources.

As of the time of Grozev's interview with Popular Politics, Beseda's phone had been switched off for two weeks, Grozev said.

Asked what has happened to those who worked under Beseda, Grozev said: "I can say that a significant number of them — if not definitely arrested — certainly no longer work for the FSB. So the 'purge' has definitely taken place."

It appears to be the latest example of Vladimir Putin's fury at his stalled invasion of Ukraine, which has prompted him to lash out at his inner circle, NBC News reported in early March.

Analysts have said that Russia's failures are in part down to miscalculations about Ukraine's political attitude and readiness to defend itself, an area that was under the purview of Beseda and the Fifth Service.