CO LOUTH, Ireland - A major Garda investigation is underway following the discovery of three members of the same family dead at a house in Co. Louth on Monday morning.

Mark O'Connor (54), his wife Louise O'Connor (56), and their son Evan O'Connor (27) were found deceased at their home in Drumgowna, Tallanstown, shortly before 10am on Monday. Gardaí were responding to a call to the rural property when the discovery was made.

The O'Connor family were well known and respected in the local community, according to Superintendent Andrew Watters of Drogheda Garda Station. "They are good neighbours and an integral part of their local community in Drumgowna and the wider areas of Louth and Monaghan," he said.

A man in his 30s was arrested nearby shortly after Gardaí arrived at the scene. He is being held at a Garda station in Co. Louth.

The incident is being treated as a homicide investigation. Gardaí have confirmed they are not seeking any other individuals in connection with the case.

The scene remains sealed off and is undergoing forensic examination by the Garda National Technical Bureau and Divisional Search Team. The Office of the State Pathologist and the Coroner have been notified. The bodies of the deceased were removed to Our Lady of Lourdes Hospital in Drogheda on Monday evening, where post-mortem examinations are due to take place later on Tuesday.

A Family Liaison Officer has been assigned to support relatives of the O'Connors, and Gardaí say they are working to support both the family and the wider community as they come to terms with the tragedy.

An Incident Room has been established at Ardee Garda Station, and a Senior Investigating Officer has been appointed to lead the inquiry.

Gardaí are appealing to anyone with information to come forward and contact Drogheda Garda Station on 041 987 4200, the Garda Confidential Line on 1800 666 111, or any Garda station.