A murder investigation has been launched following the disappearance of a Belfast woman over a year ago.
Saoirse Smyth was last seen in the city in April 2017, but her movements have been traced to Omeath in Co Louth, where she was living at the time.
Gardaí are assisting the PSNI with the investigation and have been searching the house in Omeath today.
A 40-year-old man was arrested by the PSNI yesterday evening in the Newry area on suspicion of the 28-year-old's murder.
He has been released on police bail pending further enquiries.
In December 2017, police issued a missing person appeal for information about the whereabouts of Ms Smyth.
Detective Chief Inspector Geoff Boyce said: "The investigation into Saoirse's disappearance has progressed and while keeping an open mind I now believe that the potential exists for Saoirse to have sadly been murdered".
He appealed for information about the circumstances leading to Saoirse's disappearance.
He said her family deserve to know what has happened to her.
Detective Chief Inspector Boyce said the family has asked police to issue the following statement on their behalf.
"Somebody out there must know something about what has happened to Saoirse and we would plead with anyone who knows anything to contact the Police - and Saoirse if you are out there, please contact your family and let us know you are okay".
He said: "I am particularly interested in speaking with anyone who has seen Saoirse or who has contact with her since January 2017".
Anyone with information should contact detectives at the incident room on 101 or +4428 9065 0222 if calling from the Republic.
Meanwhile, gardaí say they are continuing to search the house in Omeath this evening and door-to-door inquiries are being conducted in the area.
They are asking anyone with information in relation to the disappearance of Ms Smyth to contact the incident room at Dundalk Garda Station on 042-9388470 or the Garda Confidential Line on 1800 666 111.