Police say more charges will be laid over the assault of promising mixed martial artist Fau Vake, who died in hospital on Sunday.
City Kickboxing confirmed Vake's death, after he spent the past week at Auckland Hospital in critical condition.
The 25-year-old was waiting for a taxi on Auckland's Symonds St last Sunday morning when he was allegedly struck from behind with no provocation. Four men had already been arrested and were facing various assault charges.
"Liufau Tu'iha'aingana Vake, known as Fau Vake, died in Auckland Hospital with family by his side this morning," Detective Senior Sergeant Geoff Babe said on Sunday.
"Our thoughts are with his family at this incredibly difficult time.
"Given the man's death, further charges will be filed in due course."
Det Snr Sgt Babe said no one else is being sought as part of the investigation, but urged anyone who may have witnessed the incident to contact police on 105.
Earlier on Sunday, City Kickboxing paid tribute to their "father, son and a much-loved brother".
"It is with inexplicable sadness, almost seven days to the hour after his hospital admission, Fau's fight to find his way back to us has ended," spokesperson Mike Angove said.
Vake's injuries sparked renewed calls - including from UFC middleweight champion Israel Adesanya - for anyone who "coward punches" someone who later dies to be charged with murder.
Adesanya, who had his jaw broken in 2012 when hit from behind, said earlier this week he wanted to bring attention to the lack of legal recognition of the seriousness of the "coward punch".
"I am distraught," he said. "In the past decade, there have been numerous deaths from punches thrown when people are not looking.
"Given the massive publicity these crimes have received, no one is dumb enough to think there is not a serious risk of death.
"There is no excuse, it should be considered attempted murder or murder."
Vake's family and City Kickboxing requested privacy on Sunday.