Detective Garda Aidan Bracken who was stationed in Carbury, County Kildare, pleaded guilty at Wicklow Circuit Court last year to making a false report to gardaí, concerning threats he claimed were made against himself, family and colleagues.
According to the Irish Independent, The Circuit Court found no punishment was warranted and dismissed the charges under the Probation Act.
However the Garda Commissioner subsequently informed the detective that he was to be dismissed from the force.
Detective Bracken has gone to the High Court seeking various orders, including one preventing his dismissal.
Mr Justice Charles Meenan will deliver his decision at a later date.