Investigators from the Police Ombudsman's Office have this morning arrested a police officer.
He is being question as part of an investigation into the alleged misuse of social media by a serving police officer.
It was initiated after a decision by the Police Ombudsman, Dr Michael Maguire, to "call himself in" to investigate information he has been made aware of.
The Police Ombudsman's Office is also dealing with a number of complaints it received in recent weeks from members of the public, which include allegations that officers have leaked confidential information and posted abusive comments on social media.