The Garda Commissioner has appealed for the public's help in relation to their investigation into an alleged serious assault in Sliabh Liag in southwest Donegal.
Drew Harris said there were concerns that what he termed a "very serious offence" had taken place and that there was a person missing.
He said the investigation could be upgraded to a murder investigation if necessary.
"We would seek the community’s support in terms of information that could be provided to us in respect to that individual’s whereabouts," he said.
Commissioner Harris said he can assure the public that the investigation is being appropriately resourced "for the seriousness of the offence that we believe has happened".
"I’m satisfied there is appropriate work going on in terms of witnesses, scene and suspects in terms of that investigation," he said.
Commissioner Harris said that there is a crime scene under investigation still active at Sliabh Liag which has been closed to the public for a number of days.
"It is appropriate we do our work before it reopens. Very active work is going on in terms of the examination of that area and this is a very difficult and intricate operation that requires expert help so it will take how long it takes. It’s a crime scene and we must be sure we’ve examined it properly."
Gardaí are asking anyone who noticed anything out of the ordinary in the Killybegs/Cill Charthaigh/Sliabh Liag area between 2pm on Saturday afternoon to around 9.30pm on Sunday night to contact them.
They are trying to find the victim of the alleged assault but it is understood he has not been officially reported as a missing person.
Additional reporting Eileen Magnier
