Twenty nine men, women and children believed to be from Vietnam were found in the back of a van in Cornwall.
Police stopped the van on Friday morning on the M5 near Cullompton in Devon following reports the group of people were seen getting in the back of the vehicle after arriving on a boat.
Four men were charged with modern slavery offences after the discovery.
Frank Walliing, 72, from Colne, Jon Ransom, 63, from Kent, Keith Royston Plummer, 62, from Sheerness, and Glen Martin Bennett, 55, from Burnley, were charged with human trafficking and assisting unlawful immigration to a member state.
The men have been remanded in custody and will appear before Truro Magistrates on Monday.
Police were called just before 7.10am on Friday to Newlyn in Cornwall after receiving reports a group of people were seen getting into the back of a van.
Devon and Cornwall Police said: "The van and another vehicle were stopped by officers on the M5 near J28 just after 9am in which 29 men, women and children were located, all believed to be Vietnamese; Police and partners continue to take care of those located in the van."
