Police, Coastguard and Border officials were called to the “complex” incident in the Thames estuary at 9.15am yesterday (December 21).
Grimaldi Lines confirmed four migrants aboard the Italian registered Grande Tema threatened staff and crew locked themselves on the Bridge.
The vessel had been circling erratically in the estuary throughout the day. It had been heading to Tilbury from Nigeria.
An operation launched last night included Margate and Ramsgate RNLI, Coastguard, police, Navy and the Naval special forces unit, the Special Boat Service.
The Coastguard helicopter was at the Manston airport site and a Royal Navy helicopter was also inbound along with the National Police Air Service. A convoy of services also headed to Margate, close to the Turner Contemporary.
At around 11pm last night the vessel was boarded by the SBS.
An Essex Police spokesman said: “We have secured a vessel in the Thames Estuary.
“The vessel was boarded and secured shortly after 11pm on Friday, December 21 and will now be brought safely into dock at the Port of Tilbury.
“Four men have been detained under the Immigration Act.
“No-one on board the vessel has been injured.”
The Grande Tema is now alongside its berth.
