A gang that is thought to have smuggled hundreds of Turkish people into London has been smashed, police have said.
Eighteen people were arrested on Thursday as raids were carried out in London, Hamburg and Cologne.
Scotland Yard said they are being questioned over the alleged trafficking of people between Turkey and the UK.
The illegal immigrants, thought to have been brought in by air, road and sea, were exploited as cheap labour in cafes and takeaways in London and elsewhere.
The Metropolitan Police and European immigration officers joined forces for operation Maxim which has been more than a year in the planning.
Ten men were arrested at business premises across south London on Thursday afternoon in connection with immigration offences.
Seven men and one woman were also arrested after dawn raids in Surrey, south, west and south-east London.
They are being questioned over their alleged involvement in human trafficking and money laundering.
A further five people were arrested by immigration officials in Hamburg and Cologne.
Met Assistant Commissioner Tarique Ghaffur said: "This operation is a further example of the Metropolitan Police's commitment to tackling organised immigration crime that has a devastating effect upon London's communities.
"Working with our European colleagues enabled us to take out an entire human trafficking network; from route to source," he said.
Des Browne, immigration minister for the UK, said the success of the operation "sends a clear message that those seeking to abuse our immigration system will be caught and prosecuted".
"We will take tough action on people here illegally and those who make money by facilitating them," he said.
"This kind of racket undermines the confidence of local people and we are determined to ensure we disrupt and prosecute those responsible."