Belgium police believe migrants rescued from a shipping container were already inside when it was dropped at a European port before leaving for Britain.
Thirty-five people - including a man who later died - were discovered in a container at Tilbury Docks early yesterday morning.
Peter De Waele, spokesman for the Federal Police in Belgium, said investigators were "very hopeful" of tracking down the driver and vehicle that dropped the container at Zeebrugge port.
"We think that the possibility [is that] the victims were already on the container before it was put down in Zeebrugge because in that area it is rather impossible to put 35 people in that container," he told the Press Association.
The uncle of dead Afghan immigrant Meet Singh Kapoor says he wanted a better life for his children. Instead his children watched him die.
ITV News has spoken to the translator police used after 35 Afghan Sikhs, including 13 children, were found in a boat in Tilbury Docks.
ITV News has obtained exclusive footage of people, believed to be Afghan Sikhs, being released from a shipping container at Tilbury Docks.