The couple whose bodies may have lain undiscovered in their Co Tipperary house for more than a year may have died from carbon monoxide poisoning.
Named locally as Nicholas and Hilary Smith, the couple were originally from England and were aged 81 and 79.
Post-mortem examinations on the couple took place on Tuesday.
The discovery was made on Monday afternoon in the townland of Cloneen, near the Tipperary-Kilkenny border.
Milk found at the house has indicated the pair could have died in late 2020.
According to the Irish Examiner, investigators are looking at the possibility that the couple may have died from carbon monoxide poisoning.
Toxicology reports are likely to be the only way to tell at this stage, and these will not be ready for some time.
The fact that all the curtains had been drawn closed and there was no sign of forced entry into the house is seen by detectives as having some significance, and could suggest a number of different scenarios.
These could include murder-suicide, a double suicide or accidental death.
A leading missing-persons charity in the UK confirmed it was not aware of any alerts placed for the couple.
Gardaí said they are investigating “all circumstances”.
The scene was preserved throughout Tuesday pending an examination by the Garda Technical Bureau.
If you have been affected by any of the issues raised in this article, you can freephone the Samaritans 24 hours a day for confidential support at 116 123 or email jo@samaritans.org
Alternatively, the contact information for a range of mental health supports is available at mentalhealthireland.ie/get-support
