Police suspect synthetic cannabis caused the death of a middle-aged man in central Auckland last week, bringing the July death toll to 10.
The body of the 47-year-old man was discovered in a central city hostel on July 28.
A possible link to synthetic cannabis was being investigated, said Acting Auckland Central Police Area Commander Matthew Srhoj.
It's the 10th death in July that's being linked to synthetic cannabis use. All the cases have been referred to a coroner.
West Auckland teenager Devonte Pierce was another who died earlier in July after smoking synthetics. Friends told Newshub the 17-year-old had only recently begun using the drug, and that it was easier to buy than marijuana.
Many users have also reported suffering seizures and psychosis. St John reported up to 20 people a day were showing up at hospitals, mainly in Auckland, with life-threatening seizures.
An addiction specialist has told the Herald synthetic cannabis had "no business being called cannabis" and was more comparable to methamphetamine.