A Plunket investigation is underway following the discovery of nearly 100 20-year-old medical records in an unused Taranaki house.
The records were found in bags in a house being viewed at the Taranaki Building Removers yard.
They were handed to the District Health Board, who then returned them to Plunket.
Plunket chief operating officer Andrea McLeod said they were taking the matter very seriously.
"We do have very good robust storage systems within the organisation and certainly we are reminding staff about the importance of security and the confidentiality of private information."
Ms McLeod said they were in the process of transferring their files online, which would increase the security of the information.