Three people are being held after customs officials seized over two million contraband cigarettes smuggled into the country from China.
Officials confirmed the discovery of the €600,000 worth of cigarettes in the Tivoli Docks at Cork was significant.
Undercover officials had followed as the container was removed to a village in Co Limerick.
"Three Irish residents were stopped and taken by officials for questioning," a spokesman said. A file is now being sent to the DPP.
"It was strongly suggested that they would have been going onto the Irish market as there was a sophisticated stamp on the packages to indicate duties had been paid," the spokesman added.
The container was placed under surveillance by custom officials when it arrived at the weekend - two-weeks after it left the Chinese port.
The officials were alerted after an international surveillance operation revealed the Benson and Hedges cigarettes were hidden in a consignment of men's shirts shipped from Chinwan Port in China.
The contraband goods were first spotted in Rotterdam after Dutch customs officials X-rayed the container. They then allowed the shipment to proceed and alerted custom officials at its final destination of Cork.
The consignment consisted of men's shirts - with cigarettes concealed in the middle layers of the boxes surrounded by the packages. This is the third major seizure of cigarettes at ports around the country this year.
PA