Inmate's larynx fractured in attack: trial

A prisoner fractured the larynx and jaw of a fellow inmate during an attack in a Perth jail, a trial has heard.

Piripi Wiremu Mikaere Kingi is charged with grievous bodily harm after the alleged attack on Daniel Rolf.

Christopher Micheal Henare Poupouare is accused of being an accessory after the fact.

Prosecutor Amanda Forrester told the District Court of Western Australia in her opening submissions on Monday that Kingi put Rolf in a vice grip until they both fell to the ground, where Kingi kneed Rolf in the chin.

Ms Forrester said Poupouare went to Rolf's cell shortly after the assault, which took place in one of the prison's common areas, to seek an assurance Rolf would not tell the guards and take away his bloody shirt.

Kingi's lawyer, Terry Dobson, said his client admitted to a physical altercation, but said it was an exchange of punches.

"It was a fight ... a fight started by Mr Rolf," he told the jury.

"Mr Rolf came off second best.

"We say Mr Kingi's use of force was lawful."

Poupouare's lawyer, Robert Grayden, said his client did not see the fight, a Serco guard could not tell from CCTV footage what he had in his hand when he left Rolf's cell and there was a question as to what he knew about the incident.

The trial continues.