Tadgh Farrell and his grandaunt, Mary Holt.RollingNews.ie

A murder investigation was launched on Sunday following the deliberate house fire, which was started in a "callous attack" at Castelview Park, Edenderry, Co Offaly, on Saturday evening.

Four-year-old Tadgh Farrell and his grandaunt, Mary Holt, 60, were fatally injured in the horror incident, with another woman aged in her 50s currently in critical condition.

A statement from An Garda Síochána confirmed that they had launched a murder investigation on Sunday.

They said: ‘Emergency services, including Offaly Fire and Rescue Service, National Ambulance Service and Gardaí [police] responded to the fire shortly before 7.54pm.

"The fire was extinguished and the remains of two persons, a woman aged 60 and a 4-year-old boy, were discovered deceased.

"A second woman, aged in her 50s, was transported from the scene by the National Ambulance Service and is receiving hospital treatment for serious injuries."

 The statement added that the house was declared a crime scene and is subject to technical examination by the Garda Technical Bureau.

Both the office of the Local Coroner and the State Pathologist have been made aware of the tragedy, with Assistant State Pathologist Margot Bolster carrying out post-mortems on the deceased on Sunday.

Gardaí confirmed their belief that the fire was started deliberately, writing that they believed the house was "attacked by a person or persons unknown at this time."

"Gardaí in Offaly are appealing for any person with any information on this fatal incident to speak with investigating Gardaí," they appealed.

"Gardaí want to speak with any person who was in the vicinity of Castleview Park, or adjoining roads between 7.00pm and 8.00pm on Saturday, 6th December 2025."

They added: "Gardaí want to speak with any person who was driving in the vicinity of Castleview Park, or adjoining roads between 7.00pm and 8.00pm, yesterday, Saturday 6th December 2025, and who may have any dashcam video footage or images to contact investigating Gardaí."

Witnesses can call the investigation team at the incident room at Tullamore Garda Station on 057 932 7600, the Garda Confidential Line on 1800 666 111 or any Garda station, in particular Edenderry Garda Station.

* This article was originally pubished on Extra.ie.