Police rescued eight suspected slavery victims living in cramped conditions at a business in Cambridgeshire
Officers believe they were working at a business on Old North Road, Kneesworth for little or no money.
No one has been arrested in connection with the investigation but police said enquiries were ongoing.
The group, who were said to be living in poor conditions, were taken to a centre where they received support.
The police, fire service, HMRC, National Crime Agency and Gangmasters Labour Abuse Authority were all among the agencies involved in the operation.