A 69-year-old man from Northumberland has been arrested by customs officers after 365,000 cigarettes and almost 900kg of tobacco were discovered.
Northumbria Police stopped a van near Washington and found the duty free hand-rolling tobacco. A man was then arrested by HM Revenue and Customs.
The cigarettes were later found at a property in Northumberland and a nearby storage facility.
The haul is thought to be worth around £250,000 in evaded excise duty and VAT.
Further investigations are currently ongoing.