A Russian national has been sentenced to life imprisonment by a Finnish court for committing war crimes in eastern Ukraine in 2014.

Voislav Torden, 38, a senior member of the Russian far-right mercenary group Rusich, was found guilty of four charges by a court in the Finnish capital, Helsinki, on Friday, while he was acquitted of a fifth charge.

The charges relate to an ambush and firefight that occurred in the Luhansk region of Ukraine, which killed 22 Ukrainian soldiers and injured four others. Torden denies the allegations.

It’s the first time charges have been brought and heard in a Finnish court over allegations of war crimes in Ukraine.

Torden, previously known as Yan Petrovsky, was a founding member of Rusich, which operated in the eastern Donbas region as part of pro-Russian separatist fighting against Ukraine. Rusich is a subunit of the Wagner group.

It was alleged that, on 5 September 2014, Torden led his men as part of an ambush of Ukrainian soldiers by pretending to be Ukrainian, before setting fire to a truck and car belonging to the unit.

Twenty-one Ukrainian troops were killed and a further five injured, the indictment said.

The court in Helsinki found there was insufficient evidence to conclude that Rusich was specifically responsible for the ambush, as there were several other groups involved.

However, it found Torden guilty on all other counts, including that Torden was in charge of the Rusich mercenaries present during the ambush, who killed at least one Ukrainian soldier and injured another.

His men were also found to have mutilated a wounded soldier by “making the Rusich group symbol on his face”.

Torden was found to have distributed “degrading” images of the soldier and to have posted on social media that Rusich would “not grant mercy”.

A panel of three judges unanimously found him guilty of the latter four charges, writing that the most serious – of killing a soldier – was “comparable to murder due to its brutality and cruelty”.

While the court held that there was insufficient evidence to find him culpable for the deaths of the 21 other Ukrainian soldiers, it ordered him to pay compensation to the family of the soldier whose death he was found responsible for.

Torden has consistently denied the allegations levelled against him, Finland’s public broadcaster reports. He intends to appeal the conviction, according to national newspaper Ilta-Sanomat.

Torden was arrested at Helsinki-Vantaa Airport in July 2023, at the request of the Ukrainian government, which sought to extradite him.

That request was rejected by Finland’s Supreme Court over concerns he would not receive a fair trial in Ukraine – but he was still able to be tried in Helsinki as he was accused of crimes under international law.

Finland’s public broadcaster, Yle, reports that similar charges have been tried domestically relating to acts in countries including Rwanda and Iraq.