A man is being questioned in connection with the unsolved murder of Co Louth woman Irene White over a decade ago.
Ms White (43), a mother of three, was killed on April 6th 2005 in her Dundalk home after she received multiple stab wounds to her chest and back.
The man being held for questioning is in his 30s and was arrested in Monaghan on Friday morning.
He was taken to Dundalk Garda station for questioning under Section 4 of the Criminal Justice Act.
The suspect can be detained for up to 24 hours without charge.
Gardai believe Ms White was murdered as part of a conspiracy between a number of people, including the killer and those who asked him to carry out the murder.
The man currently detained is a third level student. His arrest has been described as significant and gardai believe they have sufficient evidence to question other people.
Despite an extensive investigation at the time including several arrests, and a further cold case review by gardaí in recent years, nobody has been charged with the murder.
According to gardaí, a man was seen running from the vicinity of Ms White’s home at about 10.15am on the morning of the murder.
Witnesses say he ran through Ice House, Hill Park, adjoining the woman’s house, into O’Hanlon Park and then escaped in a dark-coloured car that was parked there.
This suspect was described as wearing jeans, a dark jacket and peaked cap.
It is thought Ms White was in her kitchen when her attacker broke into the house and stabbed her. Her body was found by her mother at 12.30pm.
Gardaí do not believe robbery was the principal motive and believe somebody who wanted Ms White dead paid another person to murder her.
Rewards of €10,000 have been offered by the Crimestoppers organisation for information that could lead to the murder being solved.
Ms White’s children and sister, Anne Delcassian, have also made many public appeals urging anyone with information to contact the Garda and help bring the killer to justice.
They have also held vigils on the anniversary of the murder to remember Ms White and to ensure the Garda inquiry would remain in the public eye.
Ms Delcassian has said it the past she believes her sister was in fear for her life around the time she was killed and had gone to gardaí with her concerns, though this was only revealed to the family after her murder.
It is understood Gardaí have suspects in the case but have been unable to bring charges against them.
And Ms Delcassian has stated publicly in recent years that she believes she knows who killed her sister.
Since her sister’s murder she has become involved in the European Justice for Families Alliance.
It has, among other things, campaigned for new procedures that would require the DPP to reveal why they have not brought charges in cases where Garda files and evidence have been submitted to the DPP with a recommendation that a suspect be prosecuted.