The bodies of a man and a woman have been discovered at a house in O'Malley Park in Limerick.
The man and the woman, both in their 20s, are believed to have been shot.
They have been named locally as Des Kelly, who lived at the house, and Breda Waters, who was from the St Mary's park area of Limerick city.
Gardaí were called to the house at around noon and found the body of a woman in an upstairs bedroom.
The body of a man was found downstairs, close to the back door of the house.
The scene has been sealed off and gardaí will begin a forensic examination of the house this afternoon.
The State Pathologist's office has also been informed.
Gardai say a full investigation into the cause of the deaths is under way.
However, they said it is too early to say what the motive for the killings may have been.
They are appealing for witnesses who may have seen anything suspicious or heard anything at or near the house last night or this morning to contact them.