Eleven people have been arrested in Kent by police investigating a criminal gang suspected of running "a slavery operation" involving migrant workers.
Raids were carried out at 12 properties following a two-year investigation by the Kent and Essex Crime Directorate.
Large sums of cash, paperwork and documents, including passports and identity papers, were seized.
Police said the arrests were for conspiracy to people-traffic, money-launder and fraud.
Those arrested were freed on bail pending further inquiries.
They were aged between 22 and 40 and were mainly living in the Canterbury and Thanet areas of Kent, a police spokesman said.
A woman from Surrey is also being dealt with by the UK Border Agency in connection with suspected immigration offences.
Victims living at several of the properties were offered advice and support on issues such as healthcare, social services and housing.
Translators were on hand to help the victims in their native languages, including Latvian, Lithuanian, Polish and Russian.
Det Ch Insp Andrea Bishop, from the serious organised crime team of the Kent and Essex serious crime directorate, said it had been a "detailed and complex" inquiry.
"These criminals prey on and exploit migrant workers, effectively running a modern-day slavery operation."