Wagner boss Yevgeny Prigozhin has died in a plane crash in Russia.
Nine other people on board the aircraft are dead as well.
In June, the paramilitary Wagner group launched a coup against Putin that only lasted 24 hours.
For months, Prigozhin had been deeply unhappy with Putin’s handling of the war in Ukraine and ordered his Wagner group to march on Moscow.
A negotiated settlement between the Kremlin and the Wagner group put an end to the rebellion and Prigozhin agreed to go into exile in neighbouring Belarus.
Ukrainian officials suspect the Wagner group are behind a number of serious crimes committed during the course of the war - including the rape and murder.