"Inquiries about the weapon's whereabouts are continuing and we are making some good progress in our area canvass as well as speaking to witnesses and taking statements.
"We have also had about half a dozen calls from the public after our appeal for information about movements at the property, and the information provided has been helpful with our ongoing inquires."
He thanked those witnesses who have contacted police with information and strongly encouraged others who saw people or vehicles frequent the Ormond St property on the Sunday to do the same.
A 20-strong team of officers is working on the investigation and the scene examination at the property is ongoing but is expected to be completed within 48 hours.
The house was also the scene of an incident on October 23 last year, where a man was stabbed in his abdomen and face, while another man suffered knife wounds to his hand.
Mr Harrison said police were communicating with the Whatuira family as the investigation progressed and would support them as they grieved.
-Anyone with information is asked to phone Detective Constable Claire Adkins on
06 210 2201.
Information can also be provided anonymously to Crimestoppers,
on 0800 555 111.
