Waitemata Police are offering a $50 000 reward in the case of West Auckland man Brett Fraser, who was murdered last October.
Mr Fraser was killed on the night of Tuesday 21 October, at the warehouse property he shared with his flatmate in Westech Place, Glen Eden.
Police believe the incident was motivated by a cannabis robbery.
Mr Fraser's flatmate was running a cannabis growing operation at the warehouse and had recently harvested his plants.
At around 9.30pm that night, Mr Fraser's flatmate was upstairs and described hearing Mr Fraser call out to him.
He began to come downstairs but as he did so he was assaulted by a man wearing a balaclava and holding a sharp object.
He was then ordered back upstairs to show the offender where his cannabis was located.
He handed over the cannabis, but when he came back downstairs he found Mr Fraser wounded on the floor.
Mr Fraser died at the scene, and had suffered a blunt-force injury to the top half of his body.
Over the past ten months detectives have pursued a wide range of enquiries, but the majority of these possibilities have now been exhausted.
Investigators have spoken at length with more than fifty people, including associates of Mr Fraser's and possible witnesses, but to date, no information has been found that would lead to the identification of the offender/s.