A post-mortem was carried out on Tuesday on a 45-year-old Orewa man who died suddenly at the weekend.
Police officers found the man dead when they went to a Milton Road address on Sunday afternoon after a report of an attempted suicide.
A 43-year-old woman, who police say was in a brief relationship with the man, appeared in court on Monday charged with assault.
She was remanded in custody, with interim name suppression, until another court appearance on Friday.
Detective Inspector Bruce Scott says police need to make further inquiries to establish exactly how the man died.
Mr Scott says police will not know if the woman will face further charges until they finish these investigations, but they are treating the death as suspicious.