Wagner boss Yevgeny Prigozhin has been confirmed dead after genetic analysis of bodies found in Wednesday's plane crash, Russian officials said.
The Investigative Committee said the identities of all 10 victims had been confirmed and matched those on the flight's passenger list.
"According to their results, the identities of all 10 victims were determined, they correspond to the list stated in the flight list," the committee said.
Prigozhin's private plane crashed northwest of Moscow on August 25, killing all on board.
The Kremlin has denied speculation that it was to blame for the downfall.
Claims that the Kremlin gave an order to kill Prigozhin were a "complete lie", the spokesman of Russian President Vladimir Putin told the British media "BBC" two days ago.
Prigozhin - once loyal to Putin - led an armed revolt put down by his own mercenary fighters in June.
Putin at the time described the uprising as "treason", but an agreement was later reached for Wagner's mercenaries to either join Russia's regular army or go to Moscow's ally Belarus.
However, in the wake of the rebellion, many observers described Prigozhin, 62, as a "dead man walking", arguing that the Russian president would never forgive boss Wagner.
During Friday's press conference, Kremlin spokesman Dmitry Peskov told the BBC there was "a lot of speculation" about the "tragic" deaths of all 10 people in Wednesday's air crash in the Tver region, northwest of the Russian capital. .
Prigozhin and his right-hand man Dmitry Utkin, as well as five other passengers and three crew members, were aboard the Embraer Legacy 600 jet, according to the passenger list.
"In the West, of course, this speculation comes from a certain angle. It's all a lie," Peskov continued.
"We don't have many facts at the moment, the facts must be clarified during the official investigations that are being carried out now", he added.
The future of the Wagner troupe has been further thrown into doubt by Prigozhin's presumed death.