Auckland District Health Board has admitted a privacy breach involving patient information being texted to other patients' phones yesterday.
The health board said there was an issue with their system that generates SMS appointment reminders, which it is investigating as a matter of urgency.
In a statement, a spokesperson said only a small number of patients were affected, in relation to a particular service.
The data shared in the text message did not include any clinical information.
The health board has contacted the affected patients, and said it would have further information once their investigation was complete.