Labour Department chief executive Christopher Blake says more problems could still be uncovered within the organisation as reviews into its operation continue.
A State Services Commission report on the former head of the Immigration Service, Mary-Anne Thompson, found that she failed to manage conflicts of interest relating to residency applications made by relatives from Kiribati.
It also criticises the department for failing to respond to concerns about Ms Thompson's performance.
Mr Blake says three reviews, including an inquiry by the Office of the Auditor-General, may identify more problems in the department.
He says a police inquiry is also continuing into Ms Thompson's CV.