Russia has accused its mercenary chief Yevgeny Prigozhin of calling for an armed mutiny.
It comes after the chief of the Wagner Group alleged the Russian military leadership had killed 2,000 of his fighters and vowed to stop what he called its “evil”.
As a long-running standoff between him and the Defence Ministry appeared to come to a head, the ministry issued a statement, saying Prigozhin’s accusations were “not true and are an informational provocation.”
Prigozhin said his actions did not amount to a military coup. But Russia’s FSB security service opened a criminal case against him for calling for an armed mutiny, the TASS news agency said on Friday, citing the National Anti-terrorism Committee.
The Kremlin said President Vladimir Putin had been informed and that “necessary measures are being taken”.
The standoff, many of the details of which remained unclear, looked like the biggest domestic crisis Putin has faced since he sent thousands of troops into Ukraine in February last year in what he called “a special military operation.”
Prigozhin, whose private militia spearheaded the Russian capture of the Ukrainian city of Bakhmut last month, is resisting an order for mercenary groups like his to sign contracts with the Defence Ministry before July 1.
Mr Prigozhin portrays Wagner as Russia’s most effective fighting force, and has enjoyed unusual freedom to publicly criticise Moscow, but not of Putin, on whose support he and Wagner ultimately depend.
In a series of emotional audio messages over two days, Mr Prigozhin escalated his repeated criticism of Defence Minister Sergei Shoigu, a close Putin ally, and Valery Gerasimov, chief of the General Staff - by accusing them of hiding Russia’s “very serious losses on the front” from Putin.
He said in one message: “Total trash is being put on the president’s desk. Shoigu and Gerasimov have a simple approach. The lie must be monstrous for people to believe it. That is what they are doing.
“It’s all being hidden from everyone. Russia will wake up one day and learn that (Russian-annexed) Crimea has been handed over to the Ukrainians ...
“They are misleading the Russian people and if it keeps on like this we’ll be left without the most important thing: Russia.”
There was no immediate response from the Defence Ministry, which has publicly ignored previous complaints.
But it repeatedly says Russian troops have repelled all the attacks that Ukraine has launched in its two-week-old counteroffensive, inflicting a heavy cost in equipment and manpower while suffering only small losses itself.
Ukraine has reported modest advances, which President Volodymyr Zelenskiy says have been “slower than desired”.
On Friday President Zelenskiy said there would be personnel changes following an inquest into the state of Ukraine’s bomb shelters.
The nationwide investigation was launched after the deaths of three people who were locked out of a bomb shelter in Kyiv during a Russian missile strike.
“There will be personnel decisions,” Zelenskiy said in a statement, without saying who the changes would affect.
