A homicide investigation is continuing after a man in his 20s was found dead at a house in Swinford last night.
The incident occurred at the Carrabeg Estate, on the edge of the the town.
Gardaí attended the scene at around 10.50pm last night after receiving reports of a disturbance.
It is believed the victim died as a result of a serious assault.
A man in his 30s was arrested at the scene. He is being detained for questioning at Castlebar Garda Station under Section 4 of the Criminal Justice Act.
The body of the victim was removed from the house at 11am this morning and brought to Mayo University Hospital in Castlebar and the State Pathologist is due there this afternoon where a post mortem on the remains will take place.
Garda forensic teams were at the house in Carrabeg early this morning and the area remains sealed off for further examination.
The names of the men have not been released, but it's understood that both are known in the locality.
Gardaí are appealing for anyone with information to come forward, particularly anyone who was in the Swinford Town area between 8pm and 11:15pm yesterday evening.
They are urged to contact Claremorris Garda Station on 094 9372080, where an incidence room has been set up.
Local councillor Michael Smyth told Midwest News that neighbours in the estate were saddened and traumatised by the incident. They extended their sympathties to the family of the victim.
People who spoke to Midwest News said that a house in the estate, owned by Mayo county council, had been used for emergency housing for some time now and that the house was often the venue for late night parties and that gardai had been frequently called to the area over the last number of months in relation to disturbances.