GARDAI have made an arrest following the death of a man in his thirties in Castleknock, Dubin 15 overnight.
It is understood the man, who has been named as Tom O'Gorman, was found with stab wounds after Gardai were called to the house at Beech Park Avenue – he was later pronounced dead on the scene.
A man also present in the house has been arrested - the two men are believed to have been playing a game of chess prior to the fatal incident.
The arrested man is a 34-year-old, originally from Palermo, Sicily.
He is being detained at Blanchardstown Garda Station and can be questioned for up to 24 hours.
Gardai are reported to be following a 'definite line of inquiry' in the murder investigation.
Meanwhile, detectives have described the fifth violent death in the country this week as 'gruesome'.
Fr Denis O'Connor, a curate at Our Lady Mother of the Church in Castleknock, said he gave the deceased man communion over Christmas.
"He was there over Christmas. I have him Holy Communion. He used come up regularly," Fr O'Connor said.
The man had been a Minister of the Eucharist at the church for a number of years, he said.
"I pray for someone who has died tragically overnight. It's a terrible tragedy. A young man -- it's an awful sorrow.
"People are broken by it. The poor man. He was a lovely man, that's all I can day. He was a gentleman.
"It's a terrible way. Whatever happened, I don't know what happened. May God give him rest. He's with his mother and father. It's only two years since his mother went.
"His poor brother and sister, God help them," Fr O'Connor said.
The priest, who celebrated mass this morning, offered prayers for the victim.
"He was a lovely man, a quiet man. He was here every Sunday. He was a very devout man. He was well liked (in the community)," Fr O'Connor said.
He said parishioners who knew Mr O'Gorman are "absolutely distressed and upset and troubled" by the death.
The Iona Institute, where Tom O’Gorman worked on the website and as a researcher, issued a statement this evening expressing their shock at the death of the young man.
“On behalf of everyone at The Iona Institute, I would like to express our total shock and deep sorrow at the terrible and untimely death of Tom O’Gorman. Tom was a friend as well as a work colleague to us all,” the statement read.
Tom had been working as a researcher at the Iona Institute since its launch seven years ago,” it continued.
“Most of us knew him from before then, in some cases all the way back to his days at UCD.
“He was a fond and dear friend and we will all miss him. We extend our deepest commiserations to his family and above all to his sister and brother, Catherine and Paul. May Tom rest in peace.”
Mr O'Gorman was living at the family home after his mother died in 2012. His father had also passed away, and it is understood he took in a lodger in recent months to help supplement his income.
Mr O'Gorman's brother Paul is reported to be living in Donegal. His sister Catherine is based in the UK.
A post mortem examination is being carried out by Professor Marie Cassidy at the City Morgue on the body of the victim while a full investigation of the scene is being made by Gardai.