ACC claimant Bronwyn Pullar didn't gain any advantage in her dispute with the corporation by approaching its deputy chairman John McLiskie, Auditor-General Lyn Provost has reported.

Ms Pullar was at the centre of a major privacy breach at the time, because ACC had inadvertently sent her details of 6700 other claimants.

The auditor-general says she found no evidence that Ms Pullar's approach to Mr McLiskie made any difference to her injury compensation claim, but the board had no formal policy to guide it.

"Of greater concern was ACC's failure to recognise Ms Pullar's wider allegations of illegality and fraud as risks to the organisation," Ms Provost says.

"A public entity should always take allegations that threaten public trust in the organisation seriously."

Ms Provost says those deficiencies are being rectified.

ACC Minister Judith Collins has welcomed the report and says it makes clear that neither the wider board nor the chief executive were aware of the issues.

"The auditor-general found the service and purchase agreement the government has put in place will lead to a more balanced and comprehensive approach to the governance and operation of ACC."