Authorities have acknowledged a "highly regrettable" incident in which the family of a Canberra prisoner only learned of his violent stabbing after accidentally spotting him in a hospital ward with severe injuries.

Key points: David Laipato was placed in an induced coma after a prison brawl

David Laipato was placed in an induced coma after a prison brawl His family found out when they coincidentally spotted him in Canberra hospital

His family found out when they coincidentally spotted him in Canberra hospital This is the second time Mr Laipato has been assaulted in prison

Warning: Graphic images below

David Laipato was found unconscious in his cell at 4:15pm on Monday, with wounds to his head, neck and body.

David Laipato is in prison serving a sentence for assaulting his ex-partner. ( Supplied )

He was taken to the Canberra Hospital and placed in an induced coma.

But his family was not notified of his hospitalisation, and only found out several hours later when Mr Laipato's father, who was at Canberra Hospital visiting Mr Laipato's mother, recognised him.

According to the Alexander Maconochie Centre's guidelines, the officer in charge of the prison is responsible for notifying a detainee's next of kin "as soon as practicable."

A spokeswoman for the Justice Department said the "informal" identification was an "unforeseeable and highly regrettable circumstance".

"The policy and procedure was followed in this case," she said.

"Family members were coincidentally present at the Canberra Hospital and were therefore informally made aware of the admission of the detainee prior to the official notification taking place."

Corrections Minister Shane Rattenbury echoed the statement on ABC Radio Canberra, and said the situation was "unpredictable".

"The corrective services policy in these spaces is very clear. When somebody is admitted to hospital, that is when the family is notified," he said.

"In this case, the priority had been getting the detainee to hospital and treated. He was seen because the decision had been taken to admit him to hospital from the emergency department, into a ward, and he was being transferred.

"Behind the scenes, that had triggered the process for corrective services to start making contact with the family.

"To have those sort of circumstances is not something we could foresee, corrections was following the procedure.

Mr Laipato's injuries included extensive bruising and wounds to the head. ( Supplied )

"But it is a really unfortunate situation, that the family found out this way."

Mr Rattenbury confirmed that there was a police investigation underway.

"One of the things that has happened at the AMC in recent years is that we've had a significant increase in CCTV; this certainly helps with police investigations," he said.

"We have a very clear expectation that in these sorts of matters, if evidence can be obtained then charges will be pressed.

"There will be consequences for this sort of assault."

A number of detainees were involved in the incident, but the reason for the brawl is unknown.

This is the second time Mr Laipato has been assaulted in prison, where he is serving a sentence for assaulting his ex-partner.