A prisoner accused of a jail bashing has told a Canberra court he did not start the fight.
Shane Cringle appeared before the ACT Supreme Court on Thursday on a charge of assault occasioning actual bodily harm.
The 26-year-old prisoner has pleaded not guilty and told the court the complainant threw the first punch in the incident.
Cringle is accused of attacking the alleged victim in the remand section of the Alexander Maconochie Centre in October 2011.
The court heard the alleged victim was in his cell after lunch when the assault occurred. He said he was concentrating on 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.
The alleged victim told prison officers he could not identify the assailant, only that he was wearing white sneakers. Prison officers allegedly found a pair of white shoes matching the description in Cringle's cell on the same afternoon.
A forensic expert told the court that blood samples taken from the shoes strongly matched the DNA of the alleged victim.
The witness said that one sample tested was 269 billion times more likely to have come from the alleged victim than a random person.
The Crown on Thursday closed its case in the jury trial.
Cringle was called to give evidence by defence barrister Alyn Doig.
The accused man admitted he fought with the alleged victim but denied kicking him in the head.
Cringle said he went to the cell to confront the complainant after hearing allegations he had ''touched kids''. The defendant said he knew the children's father and was concerned his friend would attack the alleged victim.
Cringle said he warned the complainant to get himself moved to the protection unit for his own safety.
He said the alleged victim got upset and threw a punch.
Cringle told the court he threw two punches in return, one of which hit the alleged victim in the face.
The trial continues before Justice John Burns on Friday.