A 28-year-old man from Newark has been sentenced to death.
The court is in the eastern Donetsk region, where pro-Russian separatists declared Donetsk People’s Republic in 2014.
The court is described as ‘unrecognised.’
The men have one month to appeal their sentences.
Aidan Aslin is from Newark in Nottinghamshire, and his family said he moved to Mykolaiv in Ukraine in 2018.
He joined the Ukrainian military as a marine in 2018, became engaged to marry a Ukrainian woman, and settled in the country.
The former care worker had in the past been fighting with Kurdish armed units in Syria against Islamic State units.
Since his capture, he has appeared in photos and video footage on Russian television in which he looked bruised and swollen as he was questioned.
The BBC reports that the chair of the panel of judges who gave the death penalty has described sentence as just.
Alexander Nikulin, said the court had been guided by “not only the prescribed norms and riles, but the main, inviolable principle of justice,” according to the Interfax news agency.
Another British man from Bedfordshire, Sean Pinner, 48, has also been sentenced to death, along with a Morrocan man.
They are reportedly charged with being mercenaries. But the British men’s families say they were in Ukraine’s military.
Both British men are serving members of Ukraine’s armed forces and the UK has made clear they are prisoners of war entitled to immunity and should not face prosecution for taking part in hostilities.
On Telegram RIA News said: “The Supreme Court of the DPR passed the first sentence on mercenaries- the British Aiden Aslin and Sean Pinner and the Moroccan Saadun Brahim were sentenced to death, RIA Novosti correspondent reports from the courtroom.”
Robert Jenrick, MP for Newark described the incident as a ‘Soviet-era show trial.’