Kyiv, Ukraine – Ukraine's leader on Friday accused Russian President Vladimir Putin of being behind the death of Wagner chief Yevgeny Prigozhin in a plane crash last month.

"He killed Prigozhin, at least we all have this information and not any other," President Volodymyr Zelensky said in a speech.

He said the incident showed that the Russian leader was now "politically weak".

Prigozhin, the head of the Wagner mercenary group in Russia, died with nine other people when a plane flying from Moscow to Saint Petersburg crashed on August 23.

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Exactly two months earlier, Prigozhin had openly challenged Russia's military high command by leading a short-lived mutiny with his fighters that threatened to spiral into civil conflict amid the country's war on Ukraine. Observers have said this was the most significant challenge to Putin's rule.

Prigozhin called off the rebellion after apparently striking a deal with the Kremlin through the mediation of Belarus, but he faced no criminal prosecution.

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

Russian investigators have said they are probing all possible scenarios surrounding the crash, including premeditated murder.