Cybersecurity experts are raising the alarm after back-to-back data breaches at two New Zealand companies.

Health New Zealand has briefed Simeon Brown on a cyber incident involving Zenith Technology, the minister's office has confirmed.

A New Zealand payroll operator says it has been caught up in a "global" data security incident that has resulted in unauthorised access to some of its customers' data.

Cybersecurity experts are raising the alarm after back-to-back data breaches at two New Zealand companies.