The head of Russia’s Wagner mercenary group, Yevgeny Prigozhin, is presumed dead after a plane crash north of Moscow on Wednesday that left no survivors, Russian authorities reported.

Prigozhin led the shadowy mercenary organization and recently challenged Russia’s military leadership over the handling of the Ukraine war. A Telegram channel linked to Wagner pronounced him deceased, though official confirmation is still pending.

The crash occurred as Prigozhin was traveling from Moscow to St. Petersburg. Forensic teams recovered bodies from the wooded site, where the wreckage of the tail and other debris lay scattered.

The circumstances have fueled speculation, with some Wagner supporters blaming the Russian state and others pointing to Ukraine. Prigozhin’s death removes a contentious figure who vocally criticized the military’s prosecution of the war.

It also leaves Wagner without its founder ahead of operations in Africa and elsewhere. The group led an unsuccessful armed mutiny against army leaders in June over incompetence claims, straining Prigozhin’s relations with President Vladimir Putin.

According to flight data, the Brazilian-made aircraft showed no signs of malfunction until rapidly losing altitude in its final 30 seconds. An investigation into the cause is underway.