The father of a Brisbane teenager killed in an allegedly random attack has broken down while paying tribute to his "beautiful, brave" son.
Steven Miller addressed the media within hours of his son Cole Miller's life support being turned off at the Royal Brisbane and Women's Hospital on Monday.
"Cole was a beautiful brave, young man with his whole life left to be lived," a tearful Mr Miller said.
"He has struggled bravely in the intensive care unit of the Royal Brisbane Hospital and our family and many close friends have been by his bedside since the incident," Mr Miller said.
"He was a beautiful and brave young man."
He thanked Cole's school friends, the water polo community and the "many, many, many others" who sent messages of love and hope.
'A fine young man'
Cole Miller represented Queensland in under-20s water polo, and was a member of the Brisbane Barracudas Water Polo Club.
The team paid tribute to Cole's hard work and dedication to the sport.
"Today we are mourning the loss of a fine young man," the Brisbane Barracudas said in a statement.
"18-year-old Cole Miller was in the prime of his life, a talented young water polo player reaping the rewards of his hard work and dedication to the sport he loved."
He is the younger brother of Australian water polo player and Olympian Billy Miller.
Charges against two men to be reviewed
Detective Acting Inspector Thomas Armitt said police would be reviewing charges of grievous bodily harm against accused attackers Armstrong Renata and Daniel Jermaine Lee Maxwell.
Confirming possible options of murder, manslaughter or unlawful striking causing death, Det Insp Armitt said the tragic event was a stark reminder of why the "One Punch Can Kill" campaign began.
"There could be no better advertisement right now as to why that campaign exists," he told reporters.
Police allege Mr Miller and a friend were approached by four men, including Renata and Maxwell, in Fortitude Valley's Chinatown Mall about 3.30am Sunday.
Maxwell allegedly asked if the pair wanted to fight before throwing a punch at both, according to police allegations summarised in court by duty lawyer Tim Clements.
"It's then alleged that this co-accused (Renata) has come in from behind or from the side and that's the punch that has led to this person falling to the ground," Mr Clements said.
Renata and Maxwell both appeared in the Brisbane Magistrates Court on Monday.
Renata did not apply for bail, though his lawyer said there would be a future application.
Maxwell, a roofer, was refused bail amid concerns he would flee or reoffend.
The court heard he had no criminal history and recently moved to Brisbane from Melbourne, while his parents lived in New Zealand.
"I am satisfied that there is an unacceptable risk that if he's released on bail he will fail to appear or commit further offences," Magistrate Terry Gardiner said.
