The Department of Transport has said a review into a report on the Rescue 116 helicopter crash is still continuing, more than six months after the process was formally announced.
After an extensive and lengthy inquiry, the Air Accident Investigation Unit's draft final report was issued to interested parties last September.
In March of this year, a review board was established to examine certain findings following a request from one of the parties subject to the investigation.
The process results from a claim by the party in question that the findings reflected adversely on their reputation.
It is the first time that a review has been carried out into an AAIU inquiry.
The review board is chaired by Senior Counsel Patrick McCann, who is being assisted by an independent expert member.
It is understood that witnesses have yet to be called before the board.
A spokesperson for the department said the review was entirely independent and that it was a matter for the chairman to determine how the process would be carried out and how long it would take to complete.
The bodies of Captain Dara Fitzpatrick and Captain Mark Duffy were recovered in the days following the tragedy.
The remains of their colleagues, winch operator Paul Ormsby and winch man Ciarán Smith, remain lost at sea.
