Police believe a Northland man who died in December drank poisoned wine left in his letterbox.
(File image) Photo: RNZ / Richard Tindiller
David Davan, 67, fell ill in November and later died in Auckland Hospital.
His death was initially unexplained, but police then launched a homicide investigation.
They believe Davan was poisoned by one of two bottles left at his Herekino property, on Puhata Road, in early November.
Forensic scientists are testing the bottles.
Anyone with information about the case can speak to an officer at Kaitāia police station, or call 105 quoting file number 211114/9270, or call Crime Stoppers anonymously on 0800 555 111.