The head of Pinnacle Midlands Health is urging thousands of patients at its clinics to be vigilant about any online activity in the wake of a cyber attack last week.
The network was hacked on 28 September, affecting regional offices and GP practices across Taranaki, Rotorua, Taupō-Tūrangi, Thames-Coromandel and Waikato.
The company said, although the system breached does not contain patients clinical notes, it does hold personal information.
Chief executive Justin Butcher told Checkpoint that the hackers may have accessed information, which could include company details and personal information of patients such as names, date of birth, NHI numbers, and ethnicity.
He said the information was stolen from the system before the breach was identified on Wednesday evening.
Butcher said Pinnacle's 87 GP clinics remain operational. However, some people may experience delays contacting some of the practices.
He said, "At the moment we don't know the number of people that could be potentially impacted by this but suggest it will be a significant number."
A freephone support line is set up for people wanting further information.