An extensive search has taken place in the Isle of Doagh and Clonmany area in recent days following reports of a man entering the sea.
The man, aged in his early 70s, is believed to have entered the water at Lagacurry Beach on Saturday afternoon, 5th October.
Following land and sea searches, gardaí are appealing to the public for any information which may help with the search and recovery.
“A Family Liaison Officer has been appointed to the family and this appeal is being carried in conjunction with the man’s family on the presumption that this man is missing, presumed deceased,” a garda statement said.
The man is described as being 6ft 2inches tall. He was last seen wearing a bottle green heavy jumper, blue collared shirt, navy cords and black boots.
“Gardaí investigating this report are aware of a report of a missing male in Donegal matching this description,” the statement said.
“This is an appeal for information and it is not a call for members of the public to begin searching for this man.”
The appeal aims to alert fishermen working in the area, landowners with coastal shoreline and any persons engaged in any activity in this coastal area to be aware of this investigation and report any information to An Garda Síochána.
Searches are being conducted along the coast by Coast Guard Units from both Greencastle & Mulroy, MRCC Coast Guard Malin Head, Rescue 118 Sligo Based Helicopter, RNLI and An Garda Síochána.
The Irish Coast Guard is co-ordinating this search along with a separate search for a missing Donegal kayaker off the Gweedore coast.
A spokesperson told Donegal Daily: “The Coast Guard are coordinating declared maritime resources in support of An Garda Siochana missing person search operations.
“The Irish Coast Guard would like to express condolences to the families of those involved.”
An Garda Síochána would advise members of the public engaged in activities along the coastline or in the water to be aware of potential adverse weather conditions and take appropriate caution when partaking in these activities.
Anyone with any information is asked to contact Buncrana Garda Station on 074 932 0540, the Garda Confidential Line 1800 666 111 or any Garda Station.