Private medical notes about 90 patients - including details of a woman suffering mental illness after childbirth - were stolen from a social worker's car.
The incident has sparked a warning for health workers to keep patient notes in secure containers.
Counties Manukau District Health Board chief executive Geraint Martin has posted a blog post to health professionals advising them of their legal responsibility to protect patients' sensitive files when moving among hospital, clinics or homes.
After the theft two years ago, one patient complained to the Privacy Commissioner. In a bid to avoid litigation the commissioner and Martin have agreed on a plan for the DHB to increase care of patient files.