Millions of cheap, illegal cigarettes are flooding the market and undermining efforts to reduce smoking rates, councils have warned.
The Local Government Association (LGA), which represents 370 councils in England and Wales, is calling for courts to impose bigger fines for selling illegal cigarettes, which it said cost the UK economy more than £2billion a year in unpaid duty.
Fake or counterfeit cigarettes are made to look like popular UK brands but typically have foreign health advisories without picture warnings on the packaging, while "non-duty paid", or bootlegged cigarettes are UK brands usually brought into the country from abroad and sold illegally.
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Recent council hauls have seen sniffer dogs used to trace bootlegged and counterfeit tobacco from the streets, while recent prosecutions resulted from illegal stashes of cigarettes found hidden in the walls and floors of shops and secret panels in cupboards.
Trading Standards officers have previously found illegal hauls hidden in toilet cisterns, in boxes of sweets, behind extractor fans and in ceiling lights.
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Simon Blackburn, chairman of the LGA's Safer and Stronger Communities Board, said: "The sale of cheap, illegal tobacco by rogue traders in shops, private homes and through social media is funding organised criminal gangs and damaging legitimate traders, as well as making it easier for young people to get hooked on smoking, which undermines councils' efforts to help people quit.
"No cigarette is good for you, but fake cigarettes contain even higher levels of cancer-causing toxins than standard cigarettes, so people should think twice about buying them.
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"Counterfeit cigarettes also fail to extinguish themselves when left to burn, presenting a real danger to people.
"Bigger fines need to be imposed by the courts to deter the sale of illegal tobacco to help councils' enforcement work against rogue traders, reduce crime in our communities and protect the health of children and young people."
Consumers who are concerned about any tobacco product on sale are encouraged to report the matter to the Citizens Advice Consumer helpline on 08454 04 05 06.