A serving Garda was among more than 100 motorists arrested as part of an extensive Garda crackdown on road safety over the Bank Holiday weekend.
The Garda, who was in uniform, was arrested at a checkpoint in Cork city centre early yesterday morning.
It is understood he failed a roadside drug test and was taken to a city centre Garda station, where he was processed and later released.
The member is due to appear in court at a later date.
A Garda source said the arrest should demonstrate to members of the public that no one is above the law.
The latest campaign was in place from 7am on Thursday, 2 April, until 7am this morning (Tuesday).
During that period, there were three fatalities on the roads, and five people suffered serious injuries in collisions.
More than 175 drivers were detected for drink and/or drug driving, while over 4,000 drivers were caught speeding.
A further 290 were caught using a mobile phone during the operation.
Gardaí continue to appeal to all road users to exercise caution at all times.
