Gardaí in Co Kerry said yesterday they were investigating the "unlawful killing" of a 38-year-old man who died yesterday, after he was assaulted on the night of the All-Ireland football final in the mid-Kerry village of Milltown
They also said that some people who witnessed the incident "could be more co-operative".
Three people have now died in the county in just over a month in suspicious circumstances, and three Garda investigations are under way.
Mr Gerard O'Leary (38), from Coolroe, Listry, Co Kerry, had been socialising in Milltown on the night of Kerry's win over Mayo.
It is understood he received a blow to the head during a fracas which involved a number of men outside a public house in the village centre sometime between midnight and 12.40 a.m. He appears to have hit his head with some force as he fell against the pavement.
Mr O'Leary, a self-employed concrete products supplier, had been with his younger brother, who was home on a visit from Australia to visit their ill mother, when the row involving two other men broke out, it is understood.
He was taken to Kerry General Hospital but was later transferred to Cork University Hospital where he underwent emergency brain surgery.
He had been placed on a life support machine and had not regained consciousness since the assault.
A post-mortem examination was under way yesterday. Leading the investigation, Insp Barry O'Rourke said "good progress" had been made to date and the Garda was following a definite line of inquiry.
"However, some people could be more co-operative," Insp O'Rourke said. There had been a number of witnesses and not all had yet come forward or had been fully co-operative.
Mr O'Leary's death is the third killing in just over a month in Kerry. Mr Michael Faulkner (43) a member of the settled Traveller community, was killed near his home at Mitchel's Crescent, Tralee, in late August.
Mr Michael McCarthy (22), Ballyspillane, Killarney, is in custody having been charged with assault on Mr Faulkner and he is due to appear in court in Cork today.
Mother of three Ms Elizabeth McCarthy (32), a member of the settled Traveller community, of Cois Coille, Tralee, was found dead on Wednesday last on the outskirts of Tralee.
Her brother, Mr Robert O'Brien (25), of St John's Park, Castleisland, was charged with her manslaughter and is to appear in court today in Tralee.