Four stowaways have reportedly threatened crew members with iron bars on-board a cargo ship in the Thames Estuary demanding they are set down near the British shoreline.
Essex Police responded to a call at just after 9am on Friday regarding the safety of crew on board a Grimaldi Lines cargo ship.
Paul Kyprianou, a spokesman for Grimaldi Group, told ITV News that four stowaways were discovered on the ship as it approached Tilbury.
The stowaways, who are believed to have boarded in Lagos where the ship left from, were locked in a cabin and given food and water in line with international regulations, Mr Kyprianou said.
But they managed to escape early on Friday morning and armed themselves with iron bars, demanding the ship's master takes them closer to the coast.
"We understand that they wanted to jump and reach the shores of the UK," Mr Kyprianou said.
The crew remain locked on the bridge of the vessel, but Mr Kyprianou said that they were safe and no one had been harmed, although they were "a bit scared".
"The master is in contact the UK authorities, with the Essex Police and the coastguard and they're trying to solve the problem," said Mr Kyprianou.
The Grande Tema, a 71,000-tonne ship, set off from Lagos, Nigeria, on December 10.
"This follows a call relating to the safety of crew on board at around 9.15am today, Friday, December 21.
"We have received no reports that anyone has been harmed and don’t believe they are at risk. We are not currently treating this as either a hostage, piracy or terror related incident.
"We are working closely with our partners to resolve this incident as quick as possible.
"We are not in a position to provide any details about who is on board at this stage."