A man in his 20s has been arrested in connection with the death of Joseph Deacy in Co Mayo last year.
Mr Deacy was found with head injuries outside a house at Gortnasillagh, Swinford on 12 August.
The 21-year-old, from St Albans in England, was initially taken to Mayo University Hospital.
He was later transferred to Beaumont Hospital, where he was pronounced dead the following day.
The man was arrested this morning and is currently being detained at Claremorris Garda Station.