A man is being questioned following the seizure of between 5m and 6m cigarettes near Dundalk last night.
The cigarettes were hidden on a container which came from Barcelona to Dublin Port last week.
They were concealed in 25 wrapped pallets along with empty boxes, and according to the documentation the 45 foot cargo was said to contain 'hair extensions'.
The cigarettes were discovered when the shipment was examined by officers as part of normal profiling.
The container had been moved around Ireland but Customs officials had been monitoring it for some time.
All were Regal brand of cigarettes and almost certainly destined for the UK markets.
The potential revenue lost to the Exchequer from the smuggled cigarettes would have been around €1.6m.
Meanwhile, six million contraband 'Souvenir' branded cigarettes were seized on Saturday.
The cigarettes which originated from Vietnam were concealed behind wooden furniture.
Several people have been interviewed and investigations are ongoing both nationally and internationally.
