The man arrested on suspicion of the murder of Miriam Burns in county Kerry has been released without charge.
Mrs Burns was found dead at her home in Killarney on Monday.
The 75-year-old’s remains were found after a relative raised the alarm.
A man in his 50s was arrested "within minutes" of a murder investigation being launched and it is believed he was known to the mother-of-four.
There was no sign of any break-in at Mrs Burns’ home and Gardaí are investigating whether she let her killer into the house.
It is believed her body lay undiscovered for several days and investigators believe she was assaulted sometime between last Friday and Monday.
The man in his 50s was released without charge this afternoon and a file is now being prepared for the Director of Public Prosecutions (DPP).
Gardaí are continuing to appeal to anyone who was in the Ardshanavooley area of Killarney between 5pm on Friday, 12th August and 1pm on Monday, 15th August to come forward if they saw anything that drew their attention.
They are particularly interested in talking to drivers who were in the area and may have dash-cam footage.
The Garda investigation is ongoing.