A Canberra man killed in his home overnight made a triple-zero call claiming to have been stabbed in the neck, the ABC has been told.
Police responded to reports of an altercation at a house in Hall Best Lane, off Flemington Road in Gungahlin about 2:00am.
They found a 56-year-old man with critical injuries and administered CPR, but he died at the scene.
A source told the ABC the victim called triple-zero before his death, saying he had been stabbed in the neck.
The source said the alleged perpetrator was apprehended after walking down the street yelling for help and saying he had stabbed someone.
Police only released limited details of their investigation, and Detective Superintendent Scott Moller said a 30-year-old man was assisting police.
"This is a horrific attack," he said.
"He had significant blood loss from the critical injuries. I can confirm it was not a shooting … the cause of death is still not determined and won't be determined until post-mortem."
Detective Moller said next of kin had not yet been notified and he could not detail the death further given the early stages of the investigation, but said no weapon had been identified.
Detective Moller said he did not know if the victim — who lived in the home where he died — was known to police or what relationship he had with the alleged perpetrator.
Officers were doorknocking homes and scouring two crime scenes on Monday morning, both next to Flemington Road.
There was a plastic box full of what appeared to be evidence sitting on the side of the road.
Police seek witnesses, footage
More than three blocks of Hall Best Lane were cordoned off by police, as detectives and forensic specialists combed the area for evidence.
Detective Moller said police were looking at one residence, certain areas of the street and a car.
"We have got multiple crime scenes. We are are looking for any evidence we might be able to find in relation to this incident," he said.
"We are looking for residents in the area at the time who might have witnessed something … this is something that ACT Policing takes very seriously and will put all our resources into."
Detective Moller said ACT Policing's criminal investigations team would be at the scene for several hours, with traffic trying to turn from Flemington Road into Hall Best Lane being diverted.
"We are calling for any witnesses, any CCTV footage from around this area or dashcam footage," he said.
"Anyone with information can contact crime stoppers on 1800 333 000."
