Auckland District Health Board staff have blundered by sending a journalist an envelope filled with personal clinical and other medical information and are now apologising to the two people involved.
It is the latest in a round of public-sector privacy errors, after clients' confidential details were found to be accessible at public Work and Income terminals around the country.
Other mistakes were the ACC's emailing of confidential information to a claimant and the Judicial Conduct Commission's sending private legal details to a Sunday newspaper.
The health board's secretary, Ian Bell, contacted the Herald after discovering it had made an error. He said the envelope was intended for the Office of the Ombudsman as part of an investigation into an Official Information Act (OIA) response.
The Ombudsman acts as the nation's keeper of secrets by ruling on what information can be released publicly and what must be kept private for reasons ranging from privacy to national security.