A post mortem will be carried out later on the body of a man who died in a County Kildare nightclub at the weekend.
Gardaí launched an investigation after they were called to a venue in Newbridge in the early hours of yesterday.
The man was found at the bottom of a flight of stairs and was later declared dead.
Elsewhere, post mortem examinations are due to be carried out on the bodies of two men killed in separate road accidents over the weekend.
In Roscommon, a 17-year-old boy died when the car in which he was a passenger hit a ditch at around 1.30am on Sunday morning.
Four other men also travelling in the car suffered minor injuries.
Meanwhile, a man in his late 20s died in hospital from injuries he received in a serious crash just outside Mullingar on Saturday afternoon.
A second man travelling in the same car remains in a serious condition in hospital while the third person received non-life threatening injuries.