Gardaí attached to the Galway Divisional Drugs Unit stopped and searched a car in the Gort area yesterday as part of Operation Tara.
Cannabis herb worth €10,000 (pending analysis) was discovered and one of the occupants of the car, a man in his 40s, was arrested.
He was taken to the North Western Regional HQ where he was detained under section 4 of the Criminal Justice Act, 1984.
He has since been released without charge.
A file will now be prepared for the Director of Public Prosecutions.
The investigation is ongoing.