Radio New Zealand journalist Phillip Cottrell was viciously beaten about the head, neck and left arm in the bashing that killed him, a post-mortem has revealed.
The 43-year-old was attacked as he walked home from work in central Wellington's Boulcott Street early on Saturday morning.
Mr Cottrell, who suffered from a degenerative bone disease, died in hospital the next day.
On Tuesday police said the post-mortem showed Mr Cottrell's injuries were consistent with "blunt impact trauma" and he had suffered multiple fractures to his head, neck and left arm, including extensive brain injuries.
It's still not known if a weapon was involved.
Police had spoken to a courier driver who was in the area at the time of the attack - he was not connected with the assault - and they are now trying to track down a man and a woman walking in the area, as well as a taxi driver.
"We do not believe any of these people are connected in any way either, but would like to speak to them to ascertain if they saw or heard anything suspicious," said Detective Senior Sergeant Scott Miller.
Security cameras in the street do not cover the area of the attack but police staff have begun trawling through a large amount of footage from other nearby cameras, he said.
Mr Cottrell was found unconscious in the street at about 5:40am by a taxi driver, 10 minutes after leaving his workplace on The Terrace on foot.
"No witnesses have seen the offenders. Our main lead is going through CCTV, it is a long and painstaking job and we collect hours and hours of it," Det Snr Sgt Miller said.
"I remain confident that we will locate those persons responsible for this vicious and cowardly attack and bring them to justice."
NZN