UK Slavery Arrest
Four men and a woman were arrested on suspicion of committing slavery offences in the raid at Greenacre travellers' site, Leighton Buzzard, Bedfordshire, on Sunday.
The men, who are English, Polish and Romanian, were found in "filthy and cramped" conditions, police said.
Detectives believe some may have been there for up to 15 years.
Those arrested are being held on suspicion of committing offences under the Slavery and Servitude Act 2010.
They are being held at police stations across Bedfordshire and Hertfordshire.
Weapons, drugs and money were also found at the site, police said.
More than 200 officers were involved in the raids.
Read more: bbc
