"As he came downstairs he has described being assaulted by a man wearing a balaclava and holding a sharp object," said Mr Bothamley.
"He was then ordered upstairs to show the offenders where his cannabis was located. He complied fully with their demands and handed over the cannabis, which was in three plastic containers, approximately 3L-sized each. The offenders fled.
"Mr Fraser lay wounded at the bottom of the stairs and despite first-aid attempts by his flatmate and emergency services, he was unable to be revived."
Mr Bothamley said Mr Fraser's flatmate was also attacked and suffered head and arm injuries.
"My flatmate, he was an innocent man, they should have left him completely alone," the flatmate said in a statement provided through police.
Police are now looking for property believed to have been stolen by the offenders from Mr Fraser's home the night he died including a pair of black motorcycle leathers, a jacket and pants.
The leathers are described as home-made, the jacket is a size 5XL and the leather pants have approximately 116cm waist.
"Our information to date suggests that Mr Fraser had nothing to do with his flatmate's cannabis activities, he was an innocent person who has been attacked and killed as a result of this crime," said Mr Bothamley.
"Someone out there may well have been offered cannabis at around the time this happened, or they may have noticed someone selling the motorbike leathers we have described. If you can help us then please get in touch."
Police are also appealing for two men who were seen in the area at the time of the attack to make contact with the enquiry team.
******
Police investigating the death of Brett Fraser want to speak to two men seen walking on Westech Pl who came from the direction of Brandon Rd at around 9.30pm on October 21.
"These men could have information that they don't realise is key to our investigation. They also need to be eliminated from the enquiry so if it's you, or you know who it might be, then please get in touch with the Op Frankfort team," said Detective Senior Sergeant James Bothamley.
Anyone with information is asked to contact Operation Frankfort on 09 839 0623.
First man:
Maori
Medium build
Tall
Full beard
Carrying a black and white-striped shopping bag
Wearing a t-shirt and black 'Dickies'-style shorts.
Second man:
Maori
Aged 20's
Shorter than the first male
Stocky build
Wearing a t-shirt and knee length shorts