Russia's most powerful mercenary Yevgeny Prigozhin was on board a plane which crashed on Wednesday evening north of Moscow with no survivors, Russian authorities said, two months to the day after he led an abortive mutiny against the army top brass.

There was no official comment from the Kremlin or the Defence Ministry on the fate of Prigozhin, head of the Wagner mercenary group and a self-declared enemy of the army's leadership over what he argued was its incompetent prosecution of Russia's war in Ukraine.

A Telegram channel linked to Wagner, Grey Zone, pronounced him dead however, and hailed him as a hero and a patriot who it said had died at the hands of unidentified people it called "traitors to Russia."

Amid fevered speculation and an absence of verifiable facts, some of his supporters pointed the finger of blame at the Russian state; others at Ukraine which was due to mark its independence day on Thursday.

A building housing Wagner's offices in St Petersburg lit up its windows after dark in such a way as to display a giant cross in a mark of respect and mourning.

Prigozhin's death would leave the Wagner Group, which incurred President Vladimir Putin's wrath in June by staging an abortive armed mutiny against the army's top brass, leaderless and raise questions about its future operations in Africa and elsewhere.

Whoever or whatever was behind the crash, his death would also rid Putin of someone who had mounted the most serious challenge to the Russian leader's authority since he came to power in 1999.

Rosaviatsia, Russia's aviation agency, published the names of all 10 people on board the downed plane, including Prigozhin and that of Dmitry Utkin, his right-hand man who helped found the mercenary group and bore the call sign "Wagner".

Russian investigators said they had opened a criminal investigation to determine what had happened. Some unnamed sources told Russian media they believed the plane had been shot down by one or more surface-to-air missiles. Reuters could not confirm that.

The aircraft, which had been travelling from Moscow to St. Petersburg, had crashed near the village of Kuzhenkino in the Tver Region, Russia's emergency situations ministry said.

US President Joe Biden said: "I don't know for a fact what happened. But I'm not surprised ... There is not much that happens in Russia that Putin is not behind, but I don’t know enough to know the answer."

Soon after the plane dropped out of the sky, a second private jet linked to Prigozhin which also appeared to be heading to St. Petersburg, Prigozhin's home base, turned back to Moscow, flight tracking data showed, and later landed.

Prigozhin, 62, spearheaded the mutiny against Russia's top army brass on June 23-24 which Putin said could have tipped Russia into civil war. Wagner fighters shot down Russian attack helicopters during the revolt, killing an unconfirmed number of pilots in a move which infuriated the military.

He has also spent months criticising the way Russia was prosecuting its war in Ukraine, something Moscow calls a "special military operation", and had tried to topple Defence Minister Sergei Shoigu and Valery Gerasimov, the Chief of the General Staff.

Many Russians had wondered how he was able to get away with such brazen criticism without consequence.

The mutiny was ended by an apparent Kremlin deal which saw Prigozhin agree to relocate to neighbouring Belarus. But in practice he had appeared to move freely inside Russia after the agreement which had reportedly guaranteed his personal safety.

Prigozhin posted a video address on Monday which he suggested was taken in Africa and turned up at a Russia-Africa summit in St Petersburg in July.

Unconfirmed Russian media reports said that Prigozhin and his associates had attended a meeting with officials from the Russian Defence Ministry.

Reuters could not confirm that and there was no confirmation from the defence ministry.

Flightradar24 online tracker showed that the Embraer Legacy 600 (plane number RA-02795) carrying Prigozhin had dropped off the radar at 6.11pm (1511 GMT). An unverified video clip posted to social media showed a plane resembling a private jet falling out of the sky toward the earth.

Another unverified clip showed the still burning wreckage of the plane on the ground. At least one body was visible. Rescuers had recovered seven bodies from the scene, TASS reported. (Reuters)