Auditor-General Lyn Provost is to investigate the ACC board's handling of former National Party insider Bronwyn Pullar's claim.
Ms Provost's inquiry is the second major inquiry into matters around the handling of Ms Pullar's claim and the massive breach of privacy that occured when the corporation mistakenly sent her the details of 6700 other claimants in August.
ACC became aware of the breach only in December when Ms Pullar met senior managers in a meeting brokered by chairman John Judge, following Ms Pullar's approach to board member and old friend John McCliskie.
Ms Provost said that approach and how it was subsequently handled would be the focus of the inquiry along with, "how ACC manages a range of risks at the board level of the organisation".
The Privacy Commission has already initiated an investigation into the major privacy breach and ACC's wider privacy procedures and policies which will be conducted by KPMG and former Australian privacy commissioner Malcolm Crompton.