A garda stationed at Finglas Garda Station has been arrested and is being questioned at Balbriggan Garda Station in Dublin.
The man, who is in his 40s, is being detained in connection with an investigation into the unauthorised disclosure of confidential information.
A woman who was also arrested has been released without charge. A file is being prepared for the Director of Public Prosecutions.
A firearm was also recovered during a number of searches.
