'An absolute gem': Young father in intensive care following alleged 'coward punch'

Kairan Mahia is in hospital fighting for his life after an alleged assault at the weekend. Photo / GoFundMe

A young father of two is in an induced coma at Royal Perth Hospital after he was allegedly assaulted in what's believed to have been a "coward punch" attack.

Kairan Mahia, 29, a fitness instructor and former international rugby player for the Cook Islands, was found with serious head injuries at the Sorrento Quay car park in the Hillarys area of the West Australian capital early on Sunday morning.

It is believed he was trying to help a woman who he didn't know who was involved in an altercation in the car park, when he was allegedly punched from behind.

West Australian police said they were called at about 4.30am to reports of a large number of people creating a disturbance and several people fighting.

Officers found Mahia in the car park and he was taken by ambulance to the hospital, where he has been in intensive care.

Police on Sunday said he was in a "critical but stable condition".

James Clarke, the owner of the fitness business boot camp where Mahia works, described him as a great guy and a lovely family man.

"He's an absolute gem. Everyone who knows him would vouch for that," he told Perth's 6PR radio.

Clarke said he believed his friend had been hit from behind by a so-called "coward punch" to the head.

He has set up a fundraiser to support Mahia's family while he is in hospital, which has raised more than $28,000.

"Kairan is one of our friends, the best employee and team member, and an all-round great guy," Clarke wrote on the GoFundMe.

"Kairan has a wife and two young daughters who must now try and hold their lives together while he fights for his.

"We look forward to seeing you soon, Kairan. Hang in there, buddy!"

WA detectives have said numerous people were in the area at the time and investigators are urging anyone who saw the incident to come forward and contact Crime Stoppers.