Pinnacle Midlands Health is still investigating a major cyber attack in which hackers stole patient data from up to 450,000 people across the North Island.
The attack comes less than a year after the Government announced $75 million in funding to boost cyber security in the health system.
Pinnacle chief executive Justin Butcher told Morning Report they are unable to update yet how many people have been affected.
He says they have a fair idea of how the breach occurred, but declined to provide details.
Butcher says they are confident that patient notes are not compromised.
