Gardaí have spoken with a man known to a mother and her two children whose bodies were found in south Dublin on Wednesday.
The bodies of the 37-year-old woman, her 11-year-old daughter and six-year-old son were found in a house in Llewellyn Estate in Ballinteer.
Post mortems are due on their bodies on Thursday, but Gardaí have deployed the resources of a murder investigation to examine the case.
A candlelit vigil was held in the estate on Wednesday night for the family, who had not been seen in a number of days.
Justice Minister Helen McEntee offered her condolences to the family.
"Obviously there is an ongoing investigation but just to offer my condolences to the families that are affected by this," she said.
"Just to say that it is a very tragic incident and we will support the Gardaí in their work in this regard."