Millions of fake cigarettes are entering the UK and undermining efforts to cut smoking, councils have warned.
Herefordshire, Lincolnshire and Durham county councils in 2018 found illegal stashes of cigarettes behind shop walls, in sweet boxes and toilets.
Fake or "bootlegged" tobacco products are sold on the black market to avoid paying duty, the Local Government Association (LGA) said.
The illegal trade diverts £2.1bn a year in tax from HM Revenue and Customs.
In one case, Peterborough man Karwan Salim Ahamed was sentenced last month after using fake Facebook profiles to sell illegal cigarettes on the social media site's "Lincolnshire + Boston + Spalding + Skegness + Sleaford + Kirton + Heckington etc" group.
Mr Ahamed was ordered to do 200 hours community service and pay £5,000 in costs.
The LGA, which represents 370 councils in England and Wales, is calling on the government to increase fines and penalties for those found guilty of trading in fake or tax-free cigarettes and tobacco.
