A group of ACC call centre workers shared details, and made fun of, people's injuries in a private Snapchat group called 'ACC Whores'.
One of the posts shared among more than a dozen employees included the name and contact details of an athlete who has represented New Zealand on the world stage.
Twelve staff have been stood down while the agency investigates. The revelation comes as ACC's privacy controls are in the spotlight after a series of stories by RNZ about the way the agency manages sensitive information.
Here's investigative journalist Anusha Bradley with the story.