A private ceremony was held to commemorate Russian mercenary chief Yevgeny Prigozhin, his spokespeople said on Tuesday, urging mourners to pay their respects at a cemetery in his native city Saint Petersburg.

Last week, Prigozhin died in a private jet crash along with nine other people, two months after ordering his troops to topple Russia’s military leadership.

The Kremlin has dismissed speculation that it orchestrated the crash in revenge for Wagner’s march on Moscow in June.

“Yevgeny Viktorovich’s farewell was held in a closed setting. Those wishing to say goodbye can visit the Porokhovskoye cemetery,” Prigozhin’s press service said in a statement, without specifying whether the mercenary chief, who was 62, had been buried.

Observers said the decision by the founder of the Wagner private fighting force to turn his troops on Moscow was the most significant direct challenge to President Vladimir Putin’s authority since he came to power.

Putin, who has accused Prigozhin of treason, said last week that he had known the ex-convict since the early 1990s, describing him as a man who made mistakes but “achieved results”.

But Putin’s comments did little to stem mounting questions over Prigozhin’s death, with makeshift shrines to the Wagner chief springing up across Russian cities.

The Kremlin said earlier on Tuesday that the Russian leader would not attend Prigozhin’s funeral.

“The president’s presence is not envisaged,” Kremlin spokesman Dmitry Peskov told reporters.

There were no public announcements of when or where Prigozhin would be buried.

Russian officials opened an investigation into air traffic violations after the crash but have not disclosed details about a possible cause.

The Wagner outfit had taken a prime role in Putin’s offensive in Ukraine, taking on the most dangerous frontline work, as the regular army appeared to falter, while sustaining what Western sources have described as colossal losses.

Unlike Russia’s generals, who have been criticised for shirking the battles, the stocky and bald Prigozhin regularly posed for pictures alongside mercenaries allegedly on the front lines.

Prigozhin was allowed to openly recruit new members in Russian prison camps and savaged the Russian defence ministry.

Political commentators said that, with next year’s presidential election in Russia approaching fast, Prigozhin had become a liability for the Kremlin.

Prigozhin has been described as a billionaire with a vast fortune built on state contracts, although the extent of his wealth is unknown.

He rose from a modest background in Russia’s former imperial capital to become part of an inner circle close to Putin.

He spent nine years in prison in the final period of the USSR after being convicted of fraud and theft.