An Adelaide man killed in a vicious assault was the victim of a targeted attack, police say.
The body of Nathan Russell was found by a friend inside his central Adelaide unit on Tuesday night.
It's believed the 46-year-old was killed sometime in the previous 24 hours, but detectives have declined to reveal the nature of his injuries for operational reasons.
Detective Inspector Brett Featherby said inquiries were continuing but it was thought that Mr Russell was targetted by his killer or killers.
"There's no doubt they intended to assault him. Whether they intended to kill him, I can't comment on that until the investigation is concluded," he said.
The number of people involved and the motive for the attack are yet to be determined.
There are no firm suspects.
Insp Featherby said a number of lines of inquiry were being pursued and detectives were keeping an open mind.
"Investigators believe that people have knowledge of what has occurred to Nathan and knowledge of the circumstances leading up to his death," Insp Featherby said.
"We're seeking anyone with information to come forward and do the right thing by his family."
Insp Featherby said investigations were continuing into whether or not there were signs of forced entry to the Sturt Street unit.
A number of items had been seized from the unit and from the immediate area with the forensic examination of the scene still underway.