Searchers used a mannequin in their bid to find a body believed to have been thrown off cliffs at Slieve League in Co Donegal.
A week after a search was launched, gardaí and the Coast Guard recovered a body in the water at the popular tourist spot around 4am on Monday morning.
The emergency services faced searching a dangerous area which are the scene of Europe's highest sea cliffs.
However, in a bid to find out if the body was in the water, searchers used a mannequin which they launched from the top of Slieve League.
It is believed the mannequin was thrown from close to an area where a blood-soaked blanket was earlier found during the search for the missing person.
It is understood the replacement 'body' ended up in the water off the cliffs allowing the emergency services to search in the area.
Gardaí and other searchers then spent a number of days scanning the water around the cliffs in the hope of finding a body.
The exercise eventually led to the discovery of the body.
The remains were taken to Letterkenny University Hospital where a postmortem was undertaken by the State Pathologist's office.
In a statement on Tuesday afternoon, gardaí said the results of the postmortem were not being released for operational purposes.
Officers have set up an incident room at Ballyshannon Garda Station under the direction of a senior investigating officer.
Although the identity of the body has not yet been confirmed, it is understood to be that of a man in his mid to late 60s from Northern Ireland.
The man is understood to have been socialising in the Kilcar, Glenties or Slieve League area in the days leading up to the weekend of June 25th/26th when he disappeared.
He was understood to have been seen in the company of a man and a woman.
The pair, a man in his late 30s and a woman in her late 20s, were subsequently arrested on Monday morning last week.
The woman was quizzed at Ballyshannon Garda Station while the man was questioned at Letterkenny Garda Station before both were released without charge within a short time of each other on Tuesday evening.
A jeep-type car belonging to the man is still being held and examined by Gardai as part of their investigation int the alleged serious assault and the discovery of a body.
Splatters of blood found in the car will play a major role in the direction of any criminal investigation when cross-matched with DNA taken from the body recovered from the sea.
A house in the Killybegs area which has direct links with the man arrested was also sealed off and examined by Gardai as part of their investigation.
'Upsetting news'
Local county councillor Niamh Kennedy said at least now there is some form of closure following a week of searching.
"It's really sad and upsetting news for the entire area. People are relieved that a body has been found and there can be some sort of closure for the family.
"A formal identification will have to be done now and gardaí have appealed for any possible footage to come forward so they can piece the whole thing together.
"As I said, it has been a traumatic time for everyone so my condolences go to everyone involved," she said.
A garda spokesperson again appealed for anybody with any information on anything out of the ordinary in the area to come forward.
The spokesperson said: "An Garda Síochána are continuing to investigate all the circumstances of an alleged assault that is reported to have occurred in the Slieve League/Killybegs area of County Donegal between Saturday 24th June 2023 and Sunday 25th June 2023.
"Investigating Gardaí are appealing to any persons travelling in the vicinity of Killybegs/Slieve League between the afternoon of Saturday 24th June 2023 and the evening of Sunday 25th June 2023 who observed any activity which drew their attention to come forward.
Any road users travelling in these areas at these times who may have camera footage (including dash-cam) are asked to make this footage available to gardaí.
"Anyone with any information is asked to contact Ballyshannon Garda Station on 071 985 8530, the Garda Confidential Line on 1800 666 111, or any Garda station."
