"Once the audit is completed, the department will act on any recommendations or findings."
Corrections is the third agency to carry out a review into Harrison's work since she was convicted in February.
The Ministry of Transport opened an investigation earlier this month following allegations from ministry staff that they were forced out of their jobs after raising concerns about Harrison's behaviour.
That investigation has now been taken over by the State Services Commission after staff complained about the ministry's handling of the issue.
The Department of Conservation also employed Harrison to carry out an inquiry into harassment allegations in 2015.
Corrections is reviewing her inquiry, though it says she was not the lead decision-maker and that the findings are unlikely to be compromised.
Auditor-General Martin Matthews, who was previously Secretary of Transport, stood down last week so his handling of the fraud case could be investigated.