More than 28,000 cigarettes and three kilos of hand-rolling tobacco were seized from Blackpool shops in a series of raids.
Half of the 12 premises visited by customs officials had stock taken as part of a crack down on counterfeit tobacco.
All the goods recovered are thought to be illicit.
HMRC, which carried out the raids, said the good would have been worth £10,921 to the public purse had they been properly taxed.
The premises involved have not been named.
Tim Atkins, assistant director of HMRC’s Fraud Investigation Service, said: “The sale of illegal tobacco will not be tolerated by us or our partner agencies.
“Disrupting criminal trade is at the heart of our strategy to clampdown on the illicit tobacco market, which costs the UK around £2.5 billion a year.
“This is theft from the taxpayer and undermines legitimate traders.”
The raids were part of a wider investigation that included premises in Preston and Wigan.
In total almost 45,000 cigarettes and 8,1kg of hand-rolling tobacco worth an estimated £17,924 in taxes was recovered.
Speaking at the launch of a clampdown on counterfeit tobacco and alcohol in the resort earlier this year, Mark Marshall, Blackpool Council licencing enforcement manager at Blackpool Council said “This is not an innocent bit of rule bending.
“Counterfeiters often have links to organised crime and there has been evidence of illegal immigrants being exploited.”