Seven men and a woman have been arrested after Customs officers seized 645,000 cigarettes and �69,000 in cash at an address in Bilston. Officers raided the house after seeing a quantity of boxes being transferred from a hired vehicle to a horsebox.
The boxes were later found to contain the contraband cigarettes.
The eight people were arrested at the house and �69,000 in cash was discovered and seized under the Proceeds of Crime Act.
Customs spokesman Mark Powell said: "The sale of illegal cigarettes and tobacco is a major problem in the West Midlands and we are determined to track down and seize both contraband and the profits of crime, hitting the distributors and dealers where it hurts - in the pocket.
"This illegal trade is forcing legitimate businesses to got the wall in the face of unfair competition."