Alexei Navalny was jailed last year.
Alexei Navalny, one of the biggest critics of Russian President Vladimir Putin, has claimed that Russian soldiers killed a man in Ukraine because the two shared a surname. The allegation was made in a series of tweets posted by Navalny on his official handle.
The body of 60-year-old named Ilya Navalny was found in Bucha, near Ukrainian capital Kyiv, among the more than 400 corpses left behind in the wake of Russia's retreat from the town last month.
"A passport with the surname "Navalny" lies next to the dead body on the ground. This is one of the people killed in the Ukrainian village of Bucha. Ilya Ivanovich Navalny," the imprisoned Russian opposition leader said in first of his nine tweets.
He also attached a picture of a passport in his tweet with the name Ilya Ivanovich Navalny that he said appeared to have been deliberately left next to a dead body in Bucha.
"Everything indicates that they killed him because of his last name. That's why his passport was defiantly thrown nearby," Navalny further said.
The Russian leader said he would like to call the soldiers who killed the innocent person "Putin's executioners".
"Apparently, they hoped he was a relative of mine," said Navalny.
The Russian Defence Ministry has so far not commented on the allegations.
“Well, now there will be another monument in Ukraine to those who died in the war, and the name of Ilya Ivanovich Navalny, born in 1961, will be there among others,” Navalny said in another tweet.
Millions have been forced to flee Ukraine since Russian troops invaded the country on February 24. Thousands have been killed or wounded, and towns and cities have been levelled.
The Kremlin calls its actions a "special military operation" which it claims was necessary to demilitarise and "liberate" Ukraine from nationalist extremists. Kyiv and its Western allies reject those arguments as a baseless pretext for invasion.
Navalny, who is 45, was jailed last year when he returned to Russia after receiving medical treatment in Germany following a poison attack with a Soviet-era nerve agent.
He blamed the attack on Russian President Vladimir Putin. The Kremlin denies the allegation.