Over £2 million of counterfeit clothing was seized in the Cheetham Hill area of Greater Manchester during a multi-agency operation targeting organised crime.
Police, Trading Standards and HMRC worked together under Operation Challenger on intelligence received, searching six addresses including businesses, private houses and storage units during planned action last week.
The agencies detained a total of six people for immigration offences, failure to appear at court, disqualified driving and on suspicion of assault.
Five vehicles were also seized for invalid or no insurance.
Greater Manchester Police said potential victims of modern slavery were identified and signposted to the appropriate services to receive protection and support to rehabilitate them.