An elderly man has been released after being questioned by gardaí following a major breakthrough in a 34-year-old murder investigation.
The prime suspect for the brutal strangulation of mother-of-two Marie Tierney in October 1984 was detained by detectives after new witnesses came forward to provide fresh information about the case.
Ms Tierney was a 34-year-old married woman with two children, aged 12 and 13, when she was reported missing from her home.
Her body was found in a ditch two months later but nobody was arrested in connection with her murder until yesterday morning.
Officers arrested the suspect, a man in his 70s, at his home in rural Co Kilkenny at about 8am.
The man, who was known to Ms Tierney, was taken under Section 4 of the Criminal Justice Act 1984 to Kilkenny garda station where he was questioned throughout the day.
"The man in his 70s arrested in relation to investigation into the Murder of Marie Tierney in 1984 has been released without charge," gardai said on Thursday morning. "A file will be prepared for the Director of Public Prosecutions."
Ms Tierney lived with her husband and two children at Clintstown, Jenkinstown, Co Kilkenny, where they owned a grocery store and petrol station.
She left her home on the evening of Sunday, October 21, 1984, at around 10.30pm in the family car, a Renault 18 estate, and never returned.
Her disappearance was reported by her husband to gardaí the following day and hours later the car was found at Newpark Fen, outside the city. Statements from several witnesses indicated that the car had been abandoned there at around 11pm on the Sunday.
Gardaí now believe that her killer had driven the car there after disposing of her body and left the scene on a different mode of transport.
Extensive searches were carried out by gardaí, members of her family, neighbours and friends but her body was not located until December 21, 1984, when a man walking along Bleach Road in Kilkenny discovered her decomposed remains in a ditch.
Ms Tierney was identified by her jewellery.
A post-mortem examination by then-State pathologist Dr John Harbison confirmed that she had been strangled.
A cold case review of the investigation into the murder was ordered two years ago by Chief Superintendent Dominic Hayes, after he had been appointed to the Kilkenny Garda division.
Officers involved in the review examined all of the existing evidence and statements taken.
All of the witnesses were again interviewed including Ms Tierney's husband and her children, who were then adults. A renewed appeal for help was made to the public and this resulted in several fresh statements being made, providing additional information about the movements of people on the night that Ms Tierney disappeared and sightings of cars and bicycles.
The review also led to the exhumation of the murder victim's body at Conahy graveyard in Kilkenny last October.
The body was taken to Waterford University Hospital for further examination and then re-interred.
Gardaí also made progress as a result of advances in DNA technology over the intervening period and Dr Harbison's findings were reviewed by State Pathologist Dr Marie Cassidy.
Ms Tierney's brother, John Bourke, and sister, Breda Fay, later told RTÉ that the developments had given them hope that the killer would be caught.
"To imagine your sister, that somebody would murder her. Take her life and then, that her body was dumped in a ditch," Ms Fay said.
"That somebody would do that. That person must pay for that."
Investigating gardaí have pursued more than 500 lines of inquiry and taken more than 200 witness statements.