A man ran from a Grimsby shop when Trading Standards officers found more than 8,000 illicit cigarettes.
The officers seized three large bags from the convenience store in East Marsh on September 23.
Locals tipped off Trading Standards about the shop and investigations are still ongoing.
In total, they found 8,080 cigarettes and 52 pouches of tobacco which are believed to be counterfeit.
So far ‘Operation Nightshade’ has seen more than 736,000 cigarettes seized in the North East Lincolnshire area.
Councillor Ron Shepherd, the portfolio holder for safer and stronger communities, said: “Our Trading Standards officers will continue to carry out these inspections to uncover this illegal trade in our borough.
“Honest retailers should not be in a position where they’re competing with those selling cheap, untaxed and smuggled tobacco products.
“We will pursue anyone involved in this industry and they risk being sentenced to a term of imprisonment by the court.
“We have a responsibility to tackle these issues and we will continue to do so.”
Anyone with information about the sale of illicit cigarettes is being urged to contact Trading Standards on 01472 326299.