A man who shut down Brisbane's CBD after threatening police with a gun in 2013 is in custody over the stabbing death of a man north of the city yesterday.

Nathan Frazer's body was found on Thursday morning in a Murrumba Downs street, prompting a manhunt for his killer.

Police yesterday announced they wanted to speak with 39-year-old Lee Matthew Hillier over the stabbing.

Mr Hillier sent the Queen Street Mall into lockdown in 2013, with terrified shoppers and CBD workers forced to evacuate or take cover in local businesses.

He held heavily-armed officers at bay for 90 minutes before the stand-off ended when he was shot several times with non-lethal rounds.

The then 35-year-old pleaded guilty to a string of charges including assaulting police and going armed to cause fear.

He was sentenced to four-and-a-half years in jail and at the time a Brisbane district court judge said he had a disadvantaged life and a savage drug addiction.

Sorry, this video has expired CCTV footage of Queen St Mall siege

The court also heard he had not intended to hurt anyone in the incident and the gun he brandished was not loaded.

Mr Hillier was eligible for parole in September in 2014, but police would not confirm how long he had been released from prison.

'Propensity for violence'

Detective Inspector Damien Hansen said Mr Hillier was an associate of Mr Frazer.

"Hiller is well known to us, he has a propensity for violence and therefore I would ask the public to contact us, do not approach him," Detective Inspector Hansen had said yesterday.

Police officers at the scene of the fatal stabbing in Murrumba Downs on Thursday. ( ABC News: Talissa Siganto )

A woman was with Mr Frazer when he was found dead.

"She's traumatised by the events and she's doing as best as you can expect as are Mr Frazer's children, it's a traumatic experience for them," Detective Inspector Hansen said.