90 year old Paddy Lyons was found dead at his home in Ballysaggart near Lismore last Saturday evening.
He was last seen alive shortly after 5pm on Friday.
A post mortem examination at University Hospital Waterford revealed that he had been murdered.
Gardaí arrested a man late yesterday afternoon in connection with the investigation – reports suggest the man in his mid-20's was taken into custody around the Tipp – Waterford border.
He is currently being detained at a Waterford Garda station under section 4 of the Criminal Justice Act.
Meanwhile Gardaí moved onto a property on the Waterford road in Clonmel shortly after 5 o'clock last evening.
The area remained sealed off overnight – this morning up to ten Gardaí armed with slash hooks and spades began a search of the grounds around the house.
Meanwhile Gardaí in Dungarvan are continuing to appeal for any witnesses to contact them on 058 48600, the Garda Confidential Line on 1800 666 111 or any Garda station.