From a Washington Post story by Robyn Dixon and Mary Ilyushina headlined “Russia confirms Wagner chief Prigozhin’s death after DNA tests”:

Russian investigators confirmed Sunday that Wagner mercenary leader Yevgeniy Prigozhin and top leaders of the group were killed when his plane crashed in the Tver region of Russia, announcing the results of DNA testing on the bodies of victims.

Russia’s Investigative Committee said it was continuing its investigation into the causes of the crash, although Western analysts believe the true cause may never be known because of Russia’s opaque and often politicized investigations system.