A Tipperary couple aged in their 70s may have been dead for up to a year before being discovered.
Gardaí say they are investigating all circumstances following the discovery of the bodies of the elderly man and woman on Monday at a house in Cloneen.
The couple, who were originally from England, had lived here for several years.
The alarm was raised by neighbours, who had become concerned for their welfare.
The scene has been preserved and an examination by the Garda Technical Bureau has taken place.
The offices of the State Pathologist have been notified, and post mortem examinations are set to take place on Tuesday.
Ralph Riegel is southern correspondent with the Irish Independent. He says it is not known how long the bodies lay undiscovered.
"What the Gardaí are saying is that a considerable period of time - I'm told that that's at least several weeks - it could be potentially be more than that.
"One of the major things that the Gardaí are trying to do is to determine when this couple were last seen.
"What they're doing is they're basically asking people with information to contact them.
"They're also contacting locals and neighbours in the area to try and pin down when was the last time that this couple were actually seen.
"Gardaí are saying at the moment they're keeping an open mind on the matter.
"The nature of their investigation will be determined by the findings of the post mortem.
"The bodies have not been formally identified, it's possible that dental records may be required to do that.
"We're also told that the post mortem will be quite lengthy because of the apparent period of time that has gone on between the time of the death and the discovery of the bodies".
Additional reporting: Eoghan Murphy