Vladimir Andonov, from the Wagner Group of Russian mercenaries, had also fought in Syria and Libya, say reports.
Andonov's death appeared to be confirmed by Russian military sources.
Andonov was accused of shooting Ukrainian prisoners of war during fighting in the Donbas in 2014.
A notorious Russian mercenary accused of killing prisoners of war and civilians in Ukraine has been killed, according to reports.
Vladimir Andonov, 44, who has been dubbed "The Executioner," was shot by a sniper near Kharkiv, Ukraine, on June 5, according to several Russian media outlets including the newspaper Moskovskij Komsomolets.
Zhambal-Zhamso Zhanaev, the head of Russia's Trans-Baikal Territory in Buryatia, where Andonov lived, confirmed his death to the paper and said his body will be transported back to the region to be buried.
—CHSeaton (@COSseaton) June 7, 2022
Andonov, who was known within Russia by his call sign Vakha or "the volunteer from Buryatia," gained notoriety due to his role in Russia's 2014 invasion of Ukraine and annexation of Crimea.
He is reported to have come to the Donbas in 2014 as a volunteer and was part of a unit that "liberated" the town of Logvinovo, where three Ukrainian prisoners of war were later found shot dead.
According to the website Peacemaker, which tracks Russian forces fighting in Ukraine, Andonov gave an interview about the mission in 2015 in which he boasted that "there were no survivors among the "dills,"' a Russian slur referring to Ukrainians.
He was known to be a mercenary of the Wagner Group, a Russian private military company with close ties to the Russian government that has been accused of committing war crimes and using brutal methods in Ukraine and other countries.
Following his time in the Donbas, he spent some years out of the public eye, during which he was widely rumored to have been deployed as part of Wagner units in Syria and Libya.
Last year, a survivor of a massacre in the town of Espia, Libya told the BBC that he believed he recognized Andonov as one of the attackers that shot his family dead.
Meanwhile, Ukrainian officials have claimed its forces destroyed a Wagner Group military base in the eastern Luhansk region, killing 22, Ukrainian news outlet Hromadske said.
—Serhiy Hayday (@serhey_hayday) June 10, 2022
Head of Luhansk regional military аdministration, Serhiy Haidai, shared a video of a burning building at a football stadium in Kadiivka which was the site used by the Wagner Group.
"The Armed Forces of Ukraine launched a well-aimed attack on it. Only one survived," Haidai tweeted.
Read the original article on Business Insider