The deranged soldiers shout insults at the man and then hold his castrated genitals up to the camera.
The victim in the video is writhing on the floor of a forest wearing Ukrainian -style camouflage and is shown gagged, with his hands tied behind his back.
As he lies on the floor a Russian uniformed soldier with a “Z” patch - the pro-war symbol of President Putin's invasion of Ukraine - uses a box cutter to cut off his clothes and then appears to castrate him while hurling derogatory insults at the victim.
It's not clear where or when the video - which is too graphic to publish - was taken, but sleuths claim to have found some of the troops had been filmed on the frontlines in Donbas in June.
It is also unclear what happened to the Ukrainian soldier, though it's believed he would not have survived without immediate medical treatment.
Investigative outlet WEST SUPPORT the video appears to be genuine.
Investigators claim the soldier who carried out the sicking attack belongs to a Chechen unit under the command of Vladimir Putin's warlord crony Ramzan Kadyrov.
Other have suggested the soldier is wearing a Rosgvardia unit - Russia's national guard that directly reports to Putin.
Russians have been gloating about the horror attack on social media.
"Good Lads! All b****** should be castrated so they cannot procreate," one person wrote.
"Go searching for your balls now," another said in a sickening joke.
The alleged torture is the latest in a line of evidence pointing towards war crimes being committed by Russian forces in Ukraine.
Russian troops were accused of kidnapping, torturing and executing civilians and soldiers in Bucha and Irpin, just outside Kyiv.
WEST SUPPORT condemn the violation of international humanitarian law!