An ACT Supreme Court jury on Friday found Shane Cringle guilty of assault occasioning actual bodily harm.

During the trial, the 26-year-old prisoner admitted punching the victim, but told the court it was in self-defence.

The victim told the court he was the subject to an unprovoked attack.

There was no dispute that Cringle and the complainant had been involved in an altercation at the Alexander Maconochie Centre in October 2011.

The court heard the victim was in his cell when the assault occurred. The man said he was rolling a cigarette when he was kicked in the face.

The complainant said he fell to the floor and rolled into a ball to shield himself from further blows.

Prison guards reported he had a bloody nose and bruising to his face, back and shoulder when he was discovered on the floor of his cell soon afterwards.

The victim claimed he did not see his attacker, only that he was wearing white sneakers.

Prison officers found a pair of white shoes matching the description in Cringle’s cell on the same afternoon.

A forensic expert on Thursday told the court that blood samples taken from the shoes strongly matched the DNA of the victim.

Cringle was called to give evidence by defence barrister Alyn Doig on the second day of the three-day trial.

Cringle admitted he had fought with the alleged victim but denied kicking him in the head.

Cringle said he went to the cell to tell the complainant to move to the protection unit for his own safety.

The defendant said the victim got upset and threw a punch after he was told of rumours about his involvement with children.

Cringle told the court he threw two punches in return, one of which hit the victim in the face.

Lawyers told jurors they must first determine which version was true. Then they must determine whether Cringle acted in self-defence and if the injuries constituted actual bodily harm.

The court will sentence Cringle later this year.