Greg Josephson - who established Australian fashion retailer Universal Store - was found dead inside a northern Brisbane home amid a party involving about 30 young people.
A 15-year-old boy - who was known to Mr Josephson - was charged with murder after the incident on Thursday night.
Police were called to the upmarket inner-city Brisbane suburb of Clayfield about 8.15pm and were confronted with a "confusing" scene.
A majority of the teenagers at the party were unaware of what had occurred before officers discovered Mr Josephson's body inside the home, investigators said.
"It was a confusing situation because it was a party," acting Detective Superintendent Craig Williams told reporters on Friday.
"It was confusing until all persons present sort of understood what was going on and why police were there."
The alleged killer was located on a nearby street with an injury, police said.
"At this stage the initial investigation indicates that no other persons were involved other than the 15-year-old boy," Det Supt Williams said.
He confirmed police had also located the alleged murder weapon.
The boy was taken into custody, with a number of distressed teenagers at the party helping police with the investigation.
The 15-year-old was later taken to hospital.
"A number of the teens who were at the address are assisting with inquiries and were brought back to stations to have their parents contacted," Det Supt Williams said.
"It's distressing for the family. It's distressing for the community and for ... innocent people who are at the house who have nothing to do with it, so all possible supports are being offered to those people."
Acting Assistant Commissioner Rhys Wildman said there had been "some sort of altercation" before Mr Josephson was found dead.
"The investigation unfolded very quickly last night," he told ABC Radio.
The boy was charged with one count of domestic violence-related murder and refused police bail.
He was remanded in custody after his case was called in children's court on Friday, when it was adjourned until September 2.
Mr Josephson founded Universal Store with his brother Michael in 1999.
The national apparel retailer was acquired by a group of private equity investors in 2018 for a reported $100 million and two years later the business went public on the ASX.
The company is currently valued at about $570 million.
In a statement, a Universal Store spokesperson said the "sincere thoughts and condolences" of staff were with Mr Josephson's family following his death.
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