Officers from Lancashire Constabulary's licensing team and ports unit joined HM Revenue & Customs officials in the raids to seize goods on which it was suspected UK duty had not been paid.
The shops were all independent off-licences in the town’s West End area.
Among the items seized were 972 litres of beer, 33.75 litres of wine, 14 litres of vodka, 3.5 litres of whisky and 2,060 cigarettes.
A number of possible immigration offences were also discovered and will be investigated by the UK Border Agency.
PC Graeme Cheetham, licensing officer, said: "Shops that sell illicit alcohol usually do so at a knock-down price - and pay scant regard to making a responsible sale.
"This can then lead to an increase in anti-social behaviour, criminal damage and violent behaviour which is why we are working with these other agencies to crack down on this problem."