Opposition parties say the Accident Compensation Corporation failed to learn from its mistakes, after another privacy breach.
A case manager's notebook, containing clients' details and bank account numbers, was stolen from her home almost two weeks ago.
The corporation said she breached protocol by taking the notebook home.
The Privacy Commissioner last year described ACC as having an almost cavalier attitude towards client privacy.
The Green Party says the latest breach proves the underlying problems at the corporation have not changed and the public cannot feel safe about their information.
Labour said ACC Minister Judith Collins needs to get more involved to ensure the culture is changing.