According to President Vladimir Putin, explosive traces were detected in the remains of Wagner mercenary head Yevgeny Prigozhin and his crew after their plane crashed over Russia in August.
Prigozhin’s plane crashed in August between Moscow and Saint Petersburg, two months after he staged a brief rebellion against Russia’s top military hierarchy.
Kremlin critics and Western countries have suggested foul play.
Putin’s comments were the first significant update on Russia’s investigation into the crash.
“The head of the Investigative Committee reported to me a few days ago,” Putin said at a meeting of the Valdai Discussion Club.
“Fragments of hand grenades were found in the bodies of the victims of the air disaster. There was no external impact on the plane.”
According to Russian investigators, they are looking into all potential scenarios surrounding the incident, including planned murder.
Putin chastised investigators on Thursday for failing to conduct alcohol and drug tests on Prigozhin and the other nine accident victims.
He also claimed that five kilograms of cocaine were discovered at the Wagner offices following the mercenary group’s brief insurrection.
“A blood test for alcohol was not done,” Putin said.
“Even though we know that after the famous events in the (Wagner) company in Saint Petersburg, the FSB (security service) found not only 10 billion in cash, but also five kilogrammes of cocaine,” Putin said.
Prigozhin led an armed rebellion against Moscow’s military leadership in June, the biggest threat to Putin’s two-decade rule.
After the crash, Putin described him as a man who had made “serious mistakes in his life but he achieved the right results.”
The Kremlin has dismissed suggestions that it orchestrated the crash in revenge for Wagner’s march on Moscow.
Russia has a history of mysterious deaths of Kremlin opponents under Putin.