Five people have been arrested on suspicion of modern slavery offences after raids across south-east England.
A woman and four men were detained in Surrey, Hampshire, Berkshire and London on Wednesday morning.
Ninety-five Surrey Police officers were involved in the operation, in close co-operation with colleagues from the National Crime Agency.
Det Ch Insp Kerry Haddleton said a potentially large scale trafficking and slavery operation had been broken up.
"I urge anyone who has any concerns about activity relating to individuals being forced to work against their will for low or no wages, or being controlled or mistreated, to report it to us," she added.