Prigozhin, whose frequent tirades on social media belie his limited role in the war as head of the Wagner private military company, has for months been openly accusing Defence Minister Sergei Shoigu and Russia's top general, Valery Gerasimov, of rank incompetence.

But on Friday he for the first time dismissed Russia's core justifications for invading Ukraine on Feb. 24 last year in what it calls a "special military operation", in a video clip released on Telegram by his press service.

"There was nothing out of the ordinary happening on Feb. 24 ... the Defence Ministry is trying to deceive society and the president and tell us a story about how there was crazy aggression from Ukraine and that they were planning to attack us with the whole of NATO," Prigozhin said, calling the official version "a beautiful story".

"The war was needed ... so that Shoigu could become a marshal ... so that he could get a second 'Hero' [of Russia] medal. The war wasn't needed to demilitarise or denazify Ukraine."

Sitting on a chair with a giant black Wagner flag behind him, Prigozhin said the war had also been needed to enrich the ruling elite who, he said, were not satisfied with the commercial potential of part of Ukraine's Donbas region that Moscow seized control of in 2014 via a proxy separatist force.

"The task was to divide material assets (in Ukraine)," he said. "There was massive theft in the Donbas, but they wanted more."

CONTRADICTING PUTIN

Wagner spearheaded Russia's capture of the Ukrainian city of Bakhmut last month, and Prigozhin has used its battlefield success - achieved at enormous human cost - to publicly criticise Moscow with seeming impunity.

He has not, however, criticised President Vladimir Putin, on whose support he ultimately depends.

Yet his latest assertion directly contradicts the rationale proclaimed by Putin, who said when sending his tanks into Ukraine that it was to demilitarise and "denazify" a country that posed a threat to Russia, an allegation denied by Kyiv.

It is a narrative that Russian authorities defend with fines or prison terms for those deemed to have spread "falsehoods" about the war.

There was no immediate response from the Defence Ministry, which has ignored previous complaints from Prigozhin, in public at least. Nor was there any immediate reaction from the Kremlin, which has also declined in the past to comment on Prigozhin's outbursts.

Putin has, however, backed a Defence Ministry order, which Prigozhin opposes, that mercenary groups like Wagner must sign contracts putting themselves under ministry control by July 1.

Some Russian analysts have speculated that Prigozhin has political ambitions and may be angling to replace Shoigu, an idea he has always played down.

On Thursday, he had accused the top brass of lying to Putin and the Russian people about the scale of Russian losses and setbacks in Ukraine.

In Friday's video, he said Moscow could have struck a deal with Ukrainian President Volodymr Zelenskiy before the war, that the conflict had been a disaster for Russia, and that tens of thousands of young lives had been sacrificed needlessly, including members of Russia's most capable forces.

Portraying the top brass as vodka- and cognac-swilling fools who lunch on caviar, he alleged the Russian war effort was being hobbled by corruption.

"We are bathing in our own blood," he said. "Time is running out fast."