Four men have been arrested as part of an investigation into alleged smuggling of migrants across the English Channel.
Two British men, aged 65 and 49, a 42-year-old naturalised British citizen of Kuwaiti origin and an Egyptian, 33, were detained following raids in Birmingham, Blackpool and Wiltshire on Tuesday, the National Crime Agency said.
All four were arrested on suspicion of conspiring to facilitate illegal immigration.
The operation - carried out in co-operation with French authorities - follows the report of suspicious activity involving a rigid hulled inflatable boat in Ramsgate, Kent, in September last year, the NCA said.
It is suspected the boat had or was about to be used for the transportation of migrants illegally from either France or Belgium, according to the agency.
Peter Smith, branch operations manager for the NCA, said: "The arrests are the latest stage of a complex investigation into the activities of an alleged criminal network involved in moving migrants across the English Channel using small boats.
"Our inquiries will continue and we are now analysing evidence we have recovered as part of this phase of work."
Cash, mobile phones and computers were also seized by investigators.
The four men who were arrested have been bailed pending further inquiries.