"Police are currently working to establish the exact circumstances around how the man received his injuries and a team of officers will be carrying out a number of inquiries in the Birkdale area over the coming days."
This would include speaking to nearby residents in the hope they could help. A scene examination was also underway.
• Anyone who may have noticed anything suspicious in the area surrounding Verrans Rd on Wednesday afternoon, or anyone with any information that could help police should call Waitematā Crime Squad on 09 839 0697 or Crimestoppers on 0800 555 111.