Russian soldiers are treated "like dogs" and receive no training, a prisoner of war claims.
A private referred to only as Vadim, who was captured in the Ukrainian city of Kharkiv and taken to a camp in Dnipro, described most of his commanders as heartless "jackals".
The 26-year-old feels betrayed and said to speak in such a way about his country's military would be a crime back home.
He was in a Grad rocket launcher when his convoy was caught in an ambush just three days into President Vladimir Putin 's invasion in February.
Vadim was thrown from the truck by an explosion and assumes everyone else was killed.
The lorry behind him was carrying ammunition and so he quickly scrambled away, knowing it wouldn't be long before it erupted.
After crawling to a tree on the side of the road he passed out - but later woke to the sound of shells landing around him.
Shrapnel cut his thigh and he was able to wrap a bandage and eventually came across an abandoned gate house.
He squatted there for 10 days, eating biscuits he found inside and drinking from a working water tap.
Once his leg was stronger he hobbled three miles through a woodland and then stopped in a bombed out apartment complex.
He found a fridge full of food in one flat so stayed there for three days.
After spotting a Ukrainian patrol he handed himself in, walking very slowly towards them with his hands up.
He was ordered to lie down and then questioned about who he was.
Another unit then took him first to one POW camp and then a second, where he remains.
Vadim told the Sun : “Now I’ve got two options. Either I am in jail here or I will be in jail in Russia because of what I have said about the Russian army.
"A lot of people think it is the second army in the world, but we have nothing. We have no training, we have no equipment and it is a crime to say that in Russia."
Vadim - who joined the forces six years ago - said by the time his unit was ambushed it had already fired around 1,000 rockets in three attacks.
He said they knew something major was happening when they were all ordered to hand over their phones and ID papers.
They were then told to cross into Ukrainian territory and begin firing at specific co-ordinates which he said he later was told was a village with civilians.
He added: “I have thought about war crimes a lot. I believe it. Because I know how things go in my country. And because they let anyone join the army."
