A post mortem is underway at Tullamore General Hospital on the body of a woman found in Portlaoise yesterday.
The body was found by gardaí during searches for missing 30-year-old Aoife Phelan.
Gardaí last night arrested a man in his 20s in connection with her murder. He is being held at Portlaoise garda station under Section 4 of the criminal Justice Act.