Three people arrested over the murder of a woman 15 years ago were released without charge tonight.
A man in his 40s and woman in her 60s were arrested yesterday and held in custody in Tullamore Garda Station, while a man in his 60s was brought to Portlaoise Garda Station.
All were being questioned over the killing of Marie Kilmartin.
She disappeared in December 1993 and her strangled body was found in a bog drain near Portlaoise six months later.
Gardai said a file was being prepared for the Director of Public Prosecutions.
Local detectives have been carrying out a review of the murder in recent months.
Her killer had used a concrete block to weigh her body down.
Ms Kilmartin’s daughter, Aine, who was put up for adoption as a baby and never knew her mother, launched a fresh campaign appealing for information on the 13th anniversary of the murder in December 2006.