The mother of three young children, whose bodies were discovered in their South Dublin home last weekend, has been arrested on suspicion of their murder.
Conor (9), Darragh (7) and little sister Carla McGinley (3) were found in their home at Parson's Court, Newcastle, Co Dublin, last Friday evening.
The children's mother Deirdre Morley - a Dublin-based nurse - has been undergoing treatment in Tallaght hospital for a suspected overdose after she was found wandering in a disoriented state shortly before the shocking tragedy emerged.
Confirming the arrest last night, a garda spokesperson said: "A woman in her 40s has been arrested on suspicion of murder in relation to the discovery of the bodies of three children at a property in Parson's Court, Newcastle, Co Dublin on January 24.
"The woman arrested was found at the scene and has been receiving medical attention at Tallaght University Hospital following the incident.
"She is currently detained at Clondalkin Garda Station under Section 4 of the Criminal Justice Act, 1984."
In a statement earlier yesterday, the children's father Andrew McGinley spoke of his utter devastation at their loss and has urged parents to cherish every moment with their own children.
Sharing a photograph of both parents with their children for the first time, dad Andrew McGinley said "every breath is a struggle" following the tragedy.
In a statement released through An Garda Siochana, Mr McGinley said: "There are no words. There is only devastation, grief and anguish. Every breath is a struggle.
"Conor, Darragh and Carla are adored. They all had beautiful, bright futures ahead of them with family, friends and a community who love them.
"To all parents, cuddle your children whenever you get a chance, tell them how much you love them as often as you can, spend every spare minute with them reading, playing and enjoying their wonderfulness.
"The future has now become our enemy but we will battle it every day to keep the memory of Conor, Darragh and Carla alive."
He signed the statement, "Andrew".
Fr John Gilligan, who represents Saggart, the family's old neighbourhood, and Newcastle, said the statement released by Mr McGinley showed "selfless compassion and bravery" and he praised him for "bringing back light into a community in darkness".
"The words Andrew has used when we are lost for words, have helped this community," the priest said.
"He and all who loved and knew the children, have suffered a great loss. They were beautiful children and little Carla's lovely smile lit up a room, I've been told.
"It was remarkably brave for a father who has lost so much, who's enduring such pain, to release a statement to help all parents across Ireland reflect."
Fr Gilligan said the words reminded everyone that, like all other Irish families, "this father had been trying to make a living for his children".
"They worked hard as a family and moved from Saggart to a bigger house in Newcastle to give their children more room, to give them the best and it's a reflection of all the hard work they put into them," he said.
Fr Gilligan said there are 22,000 children within the communities of Newcastle, Saggart, Rathcoole and Brittas - areas which all fall under his parish.
"Family is everything to our communities and our community is rallying round to offer support. He is incredibly brave and his statement has taken my breath away," he added.
Gardai are awaiting toxicology results to determine the exact substance which is suspected of being consumed by the children.
It is not suspected that any drugs were administered to the children by injection as no visible marks were found on their bodies. However, it is suspected that some, or all, of the children may have been smothered after being sedated.
Gardai are not looking for anyone else in relation to the tragedy and have recovered two notes from the house in Newcastle including one that read "call 999, don't go upstairs".