A lorry load of black-market cigarettes worth about 3 million euro has been seized.
The massive haul of Marlboro was hidden in a shipment labelled "office furniture" which traffickers attempted to smuggle through Dublin Port.
Some 7.2 million cigarettes were recovered by customs after they carried out risk-profiling on freight trucks coming off a ferry.
Officers uncovered hundreds of cartons concealed in a 40ft container, which had arrived from Spain via Rotterdam.
It is estimated the tobacco had a street value of about 3.1 million euro and if sold on the black market would have cost the Exchequer about 2.4 million euro in lost revenues.
The Irish Tobacco Manufacturers' Advisory Committee (Itmac) warned Ireland could lose 616 million euro in taxes this year because of cigarette smuggling.
"It is a well known fact that tobacco smuggling revolves around organised criminal gangs, operating on an international scale," an Itmac spokesman said.
"This illegal trade is resulting in job losses within the legitimate retail sector and bringing crime to communities all over the country.
"Fakes look just like the real thing, even down to the Irish health warnings and the Irish tax stamp.
"People need to be aware that even though it looks like the legitimate product it may not be."