At the time of the murder Detective Senior Sergeant James Bothamley said the flatmate had been running a cannabis-growing operation inside the property and had recently harvested his plants.
The night of Fraser's death, three men reportedly arrived at the flat at 9.30pm.
The flatmate told police Fraser called out to him and as he came downstairs he saw the 51-year-old being assaulted by "a man wearing a balaclava and holding a sharp object".
"He was then ordered upstairs to show the offenders where his cannabis was located," Detective Senior Sergeant James Bothamley said at the time.
"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."
Police at the scene of Brett Gene Fraser's murder, in his Glen Eden home in 2014. Photo / Jason Oxenham
Bothamley said 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.
Despite exhaustive police inquiries and a $50,000 reward, no one has ever been arrested in relation to Fraser's murder.
Police even said they would consider immunity from prosecution for anyone who could help them find the killer.
When the reward was offered police said while Fraser had been living in a house where drugs were being grown, "no-one deserved to die on a cold warehouse floor at the hands of another".
During the investigation police spoke "at length" with more than 50 people including associates of Fraser's and possible witnesses.
Deputy Chief Coroner Brandt Shortland will preside over tomorrow's inquest.
