Russian leaders may have infuriated military officials following the arrest of former intelligence officer Igor Girkin, British defence chiefs said.
Officers from Russia’s Investigative Committee arrested Mr Girkin, an extreme nationalist militia leader turned blogger, at his Moscow flat on Friday morning.
At a court appearance in the afternoon he was detained for two months on charges of inciting extremism.
The UK’s Ministry of Defence (MoD) said in its latest intelligence update that Mr Girkin had long been a critic of the Russian defence ministry’s conduct of the war in Ukraine, but that in recent days his comments “turned to direct criticism of the Russian president Vladimir Putin and his time in power”.
Mr Girkin was a former battlefield commander of Russia’s proxy forces and was convicted by a Dutch court over the 2014 shooting down of Malaysia Airlines flight MH17.
The MoD said his arrest “is likely to infuriate fellow members of the mil-blogger community – and elements within the serving military – who largely see Mr Girkin as an astute military analyst and patriot”.
They added: “While Girkin is no ally of the Wagner Group, he was likely only prepared to push the limits of public criticism in the context of Wagner chief Yevgeny Prigozhin’s June 2023 abortive mutiny. The taboo against unmasked criticism of the Putin regime has significantly weakened.”
Mr Girkin fought as a foreign volunteer in wars in Transnistria and Bosnia in the 1990s before joining the FSB.
In 2014, he claimed credit for “pulling the trigger” on the war in Donbas when he and a group of volunteers seized control of the town of Slavyansk and proclaimed himself “defence minister” of the break away Donetsk People’s Republic.
Last November a Dutch court sentenced him to life in prison for the murders of 298 people on MH17, a Malaysian airlines Boeing 777 that a Russian Buk missile launcher shot down over Ukraine in July that year.
He fell out with the Kremlin and was forced to return to Moscow, where he founded a short-lived Right-wing political movement aimed at overthrowing Putin before turning to blogging.