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.
The police are also investigating Ms Pullar's alleged attempt to secure a two year guaranteed benefit from ACC in exchange for the return of the other claimants' details during the December meeting.
Ms Provost said she also intended to develop an audit proposal on ACC's general operations, with a focus on case management, for the Office's work programme in 2013/14.
Labour's ACC spokesman Andrew Little welcomed the inquiry as an opportunity to examine "the real problems plaguing the agency''.
"We note that while the terms of reference focus on the Board's actions and their interaction with clients and staff, there is also a clause allowing the Auditor-General to look into 'any other matters' she considers desirable. Labour hopes that will include the behaviour of ministers who have been involved in this case.''
Mr Little, his colleague Trevor Mallard and Radio NZ are the target of defamation action by ACC Minister Judith Collins regarding the MPs' claims about how an email from Ms Pullar's friend and former National Party president Michelle Boag was leaked to the media.
With at least four seperate investigations into the affair that cost Cabinet Minister Nick Smith his portfolios two weeks ago, now underway, Mr Little said Labour still wanted "a single high level inquiry by a QC or Judge''.