Sixteen people, including two children, are claiming asylum after being found at Hull docks.
They were hiding in a container on the back of an Italian-registered lorry.
Customs officials using x-ray equipment made the discovery while looking for contraband at King George Dock at 0700 BST on Sunday.
The Home Office said all 16 people are Indian nationals.
Social services are taking care of the two children while the adults are being held in police stations in East Yorkshire and northern Lincolnshire.
The nature of the cargo being carried by the lorry has not been disclosed.