A Privacy Commission official has told a Parliamentary select committee the commission knew nothing about a breach of privacy at ACC until it was approached by a journalist.
Assistant commissioner Katrine Evans says they do not know about breaches of privacy unless told about them.
The Privacy Commission is looking into how details of thousands of claims were mistakenly sent to Bronwyn Pullar of Auckland, and also how Ms Pullar's name ended up in the media.
Ms Evans later told reporters that finding out just when the ACC knew about the breach is part of the investigation into the matter.
She says if the corporation knew about the breach earlier, it should have informed the Privacy Commission.