More than 75,000 cigarettes worth almost £20,000 have been seized and a man has been arrested after raids by police.
Durham County Council trading standards officers carried out the raids on Wednesday morning in execution of warrants.
They were assisted by officers from Durham Constabulary and immigration officials.
The arrested man and a woman were interviewed by officers. The man was arrested on suspicion of being involved in the supply of counterfeit cigarettes.
In total, 77,480 cigarettes, 28.55kg of hand rolling tobacco and money were confiscated in the raids at a shop in Seaham and a home in Blackhall Colliery.
According to a press release by Durham County Council, the retail value of the cigarettes and tobacco seized was between £20,000 and £25,000.
Owen Cleugh, the council’s consumer protection manager, said: “Illegal tobacco affects our communities on many levels.
“Supplies of illegal tobacco make it easier for children to get hold of cigarettes and to start smoking.
"Children are often aware of who sells illegal tobacco locally, and at pocket money prices.
“Cheap tobacco also encourages people to keep smoking and to smoke more.
“The illicit tobacco trade is furthermore linked to serious criminality, which can have a devastating impact on communities.”
He added: “Sellers of counterfeit tobacco can face up to 10 years in prison, unlimited fines, as well as having their assets seized under Proceeds of Crime legislation.
“Those who sell it should be warned that raids like these are not a one-off and that we are committed to acting wherever we can to combat the supply of these products in our neighbourhoods.”
Anyone with information on the sale of illegal tobacco is can call the Illegal Tobacco Hotline on 0300 999 0000. This can be done anonymously.