The officer, who is serving at Blanchardstown station in west Dublin, was suspended by commissioner Noel Conroy after British police contacted gardai about the alleged incident.

The garda, who is in his mid-20s, was on a stag weekend in Newcastle on Saturday 30 June and was observed by a plainclothes officer in possession of cocaine in the toilet of a popular nightclub.

He was arrested and taken to a local police station for questioning and a small amount of the illegal drug was seized.

Police discovered his garda ID badge and contacted their counterparts in Dublin.

The young officer was officially cautioned and released and flew back to Dublin the next day.

He was summoned to a meeting of garda management the following Monday and was suspended pending the results of an internal investigation.

A superintendent from outside the Dublin Metropolitan Western Region has been appointed to examine the circumstances of how the garda came into possession of the cocaine.

A major internal audit of all the drugs seized in the area where the officer worked is underway to determine if any seizures have gone missing or were sent to garda headquarters incomplete.

It is understood that the garda was with a number of friends and there were no other gardai with him.

Sources say that garda management is "furious" over the incident which will result in more unwanted publicity for the force.