Police are yet to formally identify Mr Ulavalu, known as Soni, as the 48-year-old man who died, and do not have anyone in custody.

Detective Inspector Matt Reynolds said officers had been called to Kokomo's on the corner of Bunda and Genge streets at 12.05am on Sunday.

It is believed the altercation began inside the venue, and Mr Ulavalu died after it spilled outside.

Witnesses have said the bloody fracas moved up and down the street, with screaming and shouting, scuffles, and punches thrown.

About 35 police officers converged on the scene from various parts of the city.

The area is blanketed with CCTV cameras and police said they were reviewing footage to determine who was involved in the incident, and who else was at Kokomo's at the time.

Police remain unsure of exactly how many people were involved in the brawl that resulted in the death of Mr Ulavalu, but confirmed one other man had suffered non-life-threatening injuries.

It has been reported that Mr Ulavalu, the commander of the ACT chapter of the Comancheros, was stabbed, but Detective Inspector Reynolds said on Sunday police were still determining the cause of death.

Detective Inspector Reynolds would not rule out outlaw motorcycle gang violence as the cause of the death.

"That will form part of the investigation," he said.

"We're certainly investigating all aspects of this incident and should we see that there is involvement from OMCG [outlaw motorcycle gangs] we will direct Taskforce Nemesis to assist."

Taskforce Nemesis is ACT Policing's dedicated team to tackle outlaw motorcycle gangs in Canberra.

Mr Ulavalu was a long-time Comanchero who has previously appeared in court with the letters ACCA, a gang motto that means "Always Comanchero, Comanchero Always", shaved into his head.

He is believed to have taken over as the Canberra chapter commander in 2018 following the gang's acrimonious split with former local boss Peter Zdravkovic, who was later shot in an incident that resulted in junior Comanchero Axel Sidaros being jailed for attempted murder.

Mr Ulavalu appeared in the ACT Magistrates Court just last week as part of an ongoing hearing involving four Comancheros. He was fighting affray and assault charges linked to a 2019 incident in which the Comancheros and Nomads clashed at the Southern Cross Club in Woden.

He appeared to be in good spirits whilst in court, often asking a Canberra Times reporter during adjournments about the latest news and discussing his lunch plans.

Bloodied clothing and blood stains were all around the crime scene in the city centre on Sunday, and police had erected temporary barriers to preserve the remaining evidence while AFP Crime Scene Forensics were called to take photographs and collect samples.

About 250 metres of Bunda Street was sealed off.

One woman who did not view the incident directly described it as a "mad scene", and said she saw a body lying immobile on the ground on the pavement in Bunda Street for a lengthy period before paramedics arrived.

Senior homicide detectives were also on the scene in the early hours, and the area was expected to stay locked down until late on Sunday afternoon.

A number of tributes for Mr Ulavalu have been posted on social media, with relatives reacting to his death with shock and disbelief.