Russian investigators said on Sunday that genetic tests had confirmed that Yevgeny Prigozhin, chief of the Wagner mercenary group, was among the 10 people killed in a plane crash last week, Reuters reported. Russia's aviation agency had previously published the names of all 10 on board the private jet which crashed in the Tver region northwest of Moscow on Wednesday. They included Prigozhin and Dmitry Utkin, his right-hand man who helped found the Wagner group. "As part of the investigation of the plane crash in the Tver region, molecular-genetic examinations have been completed," Russia's Investigative Committee said in a statement on the Telegram messaging app, as quoted by Reuters . "According to their results, the identities of all 10 dead were established. They correspond to the list stated in the flight sheet," it said. There had been some speculation, especially on pro-Wagner Telegram channels, about whether Prigozhin - who was known to take various security precautions in anticipation of a possible attempt on his life - had really been on the doomed flight. Authorities have yet to say what they believe caused his private jet to fall from the sky. US and Western officials said last week that a preliminary US intelligence assessment concluded that an intentional explosion caused the crash. The crash came exactly two months after Prigozhin led a failed mutiny against Russian army chiefs. Russian President Vladimir Putin last week denied having any connection to Prigozhin’s death, as he sent his condolences to the families of those killed in the crash. Related articles: 'I survived a meal cooked for me by Prigozhin' New video shows Prigozhin days before fatal plane crash Wagner chief buried in quiet funeral Intentional explosion led to Wagner Group chief's death Putin cited "preliminary information" as indicating that Prigozhin and his top Wagner associates had all been killed and, while praising Prigozhin, said he had also made some "serious mistakes." On Friday, the Russian President ordered Wagner Group fighters to sign an oath of allegiance to the Russian state. The decree, published on the Kremlin website, obliges anyone carrying out work on behalf of the military or supporting what Moscow calls its "special military operation" in Ukraine to swear a formal oath of allegiance to Russia.