Revenue officers seized 100 kilograms of herbal cannabis, with an estimated value of €2 million, yesterday at Dublin Port.
The drugs were discovered when officers stopped and searched an Irish-registered accompanied freight unit that had disembarked a ferry from Cherbourg, France.
The search was part of an intelligence-led operation between Revenue and Gardaí, with the assistance of Revenue's mobile x-ray scanner and detector dog, Alfie.
A man in his 60s was arrested by Gardaí and is being held at a city garda station under Section 2 of the Criminal Justice (Drug Trafficking) Act 1996.
Investigations are ongoing.