The Customs seized 1,750 cartons containing 350,000 cigarettes in Vartius, Kainuu at the end of July.
Three foreigners are held in suspicion of aggravated tax evasion of an estimated 90,000 euros in this connection.
The cigarette consignment was smuggled through the Vartius Customs concealed in a truck carrying another cargo.
The consignment was being transferred to another truck on the Finnish side of the border at the time the Customs patrol arrived at the scene.
The Customs and Border Guard officers apprehended three men.
The seizure is one of the largest smuggled consignments in the north of the country.
