The Ministry of Marine Resources secretary was suspended in May this year on full pay.
It's understood the investigation was the result of a complaint laid against him in relation to last year's meeting of the Western and Pacific Fisheries Commission in the Philippines.
The Cook Islands Public Service Commissioner Russell Thomas said delays in completing the investigation were due to sourcing information from overseas, competing priorities and staffing issues.
He said other challenges were around determining technical aspects of fishery agreements and negotiations, and understanding country, regional and stakeholders positions as well as competing interests involved in the fisheries industry.
Mr Thomas expects a summary of the findings will be made public rather than the full report.