Health authorities are about to tell more than 4000 people their personal information was breached and shared on the dark web after a damaging cyberattack.
Waikato District Health Board said where possible, it would be in direct contact with the roughly 4200 affected people "from early next week".
Offshore, including a case in Finland, there have been several cases where a health organisation has refused to pay a ransom, then attackers have gone on to attempt to blackmail individual patients.
The health board said it was reviewing data disclosed on the dark web after the cyber attack in May.