Eight stowaways have been found in a lorry on a ferry bound for Hull.
The people were discovered when they got out of the back of a refrigerated lorry on the vehicle deck of the Pride of York shortly after leaving Zeebrugge, Belgium.
They told the crew they wanted to claim asylum in Britain.
How they managed to evade detection is baffling P&O Ferries, which operates the Pride of York.
X-ray checks
The lorry they were travelling in will have passed carbon dioxide sensors, which can detect people breathing, and a scanner which X-rays lorries to check for stowaways at the Belgian port.
The Pride of York has docked in Hull and the eight people are expected to formally lodge their asylum applications after being questioned by police and immigration officials.
Immigration officers say the group is believed to include seven people from India and one from Macedonia.
This latest incident comes amid claims that organised people smuggling gangs are now targeting the Humber ports because of increased security elsewhere.
On Sunday, 16 asylum seekers were found in a container at Hull docks.
Fourteen adults are still being questioned at various police stations in the area and two children are being cared for by social services.