It was initially thought that Seamus Doherty died as a result of an accident or perhaps took his own life at his home in Co Donegal.
However, following an autopsy carried out yesterday by Professor Marie Cassidy, the State pathologist, which revealed Mr Doherty had suffered a traumatic death, gardaí upgraded their investigation to a murder inquiry.
Mr Doherty, aged 67, was found dead at his home at Drumacanoo in Churchill at around 1.30am last Sunday.
A number of people had been at the house when he died, including his wife Ann.
Gardaí in Milford were contacted and Mr Doherty was found dead at the scene a short time later.
Garda Superintendent Eugene McGovern of Milford Garda Station said he was not in a position to say how many people were in Mr Doherty’s house at the time or what injuries he suffered.
“We have spoken to a number of people but there has been no arrests at this time,” he said.
“We are appealing to anyone who may know of his movements after 9pm on Saturday evening, when he got a lift out to his home, to come forward.
“Mr Doherty would have been well known in the general area and people would have remembered seeing him if they came across him,” he said.
Yesterday, there was no sign of anybody at the cottage, located 9km outside Letterkenny.
Mr Doherty has four grown-up children: Brid, Annette, Catriona, and Brian.
Locals in the Churchill and Glenswilly area, where Mr Doherty was a retired farmer, have been left stunned by the news that his death is now being treated as murder.
The dead man was known to gardaí. He had appeared in the district court on a number of occasions — mostly for public order offences.
In March, he was ordered to remain under the care of the psychiatric services after pleading guilty to assaulting Fr Michael McKeever during Mass at St Colmcille’s in Glendowan, Co Donegal, on Jan 15, 2011.
He was also found guilty of disrupting traffic while under the influence of alcohol.
His body was expected to be released to his family last night.