Detector dog Milo has helped Revenue officers to seize almost five million cigarettes at Dublin Port.
The 4.8 million cigarettes had an estimated retail value of almost €3.8 million, representing a potential loss to the Exchequer of about €3 million, Revenue said.
The smuggled cigarettes, branded Lambert & Butler, were discovered on Wednesday concealed in a consignment which had arrived from the Netherlands. The cargo had been described as plastic pipes and rubber seals.
Investigations are ongoing.
Revenue said the seizure, made as a result of routine profiling, was part of ongoing operations targeting smuggling, shadow economy activity and the supply of illegal tobacco products.
Anyone with information regarding smuggling can contact Revenue in confidence on 1800 295 295.