Police are hoping a post-mortem examination will shed some light on how a man died in a central city street in Whangarei.
Members of the public found the dead man on Bank St, between Cameron St and Vine St, shortly after 3am yesterday, and raised the alarm.
He was unresponsive and when St John arrived there was nothing they could do to revive the man, believed to be in his 30s.
Detective Inspector Kevin Burke said police believed they knew the man's identity and were working to notify next of kin before releasing his name.
Mr Burke would not say where the man was until they had contacted his family. Police had watched camera footage from the area and it was being treated as an unexplained death, and would be referred to the coroner.
He said the autopsy results would help determine why the man died.
It is the second sudden death police have been called to investigate with no suspicious circumstances.
On Wednesday, officers were called to One Tree Point area after a 76-year-old man was found in a pond on a golf course. A local resident made the discovery on Wednesday at the La Pointe estate golf course. Police have referred the case to the coroner.