Former British Prime Minister Boris Johnson claims that Russian President Vladimir Putin "must have killed" Wagner CEO Yevgeny Prigozhin, adding that no peace talks with Putin on Ukraine are possible.

PHOTO | COURTESY Boris accuses Putin of killing Yevgeny Prigozhin

Johnson speculated on Prigozhin's final moments in a Daily Mail op-ed on Saturday, just days after a plane believed to be carrying the Wagner chief crashed in a field northwest of Moscow on the way to St. Petersburg.

It is unclear what caused the plane crash, but US and Western intelligence officials with whom CNN spoke believe it was intentional.

PHOTO | COURTESY Boris Johnson 

"It can't have been more than a few seconds between the explosion aboard the otherwise reliable Embraer Legacy 600 executive jet, and the moment the Russian thug blacked out in his vertiginous acceleration to earth; and yet in that instant I am certain that he knew with perfect clarity what had happened," Johnson wrote.

"He knew whose hidden hand was sending him 28,000 ft down, to be immolated with the rest of his Wagner group companions in a fireball in the countryside of the Tver region north of Moscow – and then on downwards, of course, for the shade of Prigozhin: down, down to Hades and the Tartarean pit below." he added.

PHOTO | COURTESY Boris Johnson 

"As the detonation sucked the air out of the aircraft's cabin, I would wager that the last thought in the doomed dome of Prigozhin's skull was 'Putin!', preceded by one of the many profanities in which the former jailbird and hotdog salesman was so fluent," Johnson wrote.

The jet crash that killed Prigozhin occurred two months after the Wagner boss led a brief insurrection in Russia.

PHOTO | COURTESY Yevgeny Prigozhin

The Kremlin said on Friday that all relevant investigations, including DNA testing, were ongoing to ascertain whether Prigozhin was killed in the incident on Wednesday. Dmitry Peskov, a Kremlin spokesman, categorically rejected any involvement by Russian authorities.

Putin stated that he had known Prigozhin "for a very long time," and was "a talented man, a talented businessman."