According to Sky News, Stena Horizon goes between Cherbourg in France and Rosslare in Ireland. The 16 people were discovered by an employee on the ferry when he heard how it knocked from inside the truck compartment in connection with a routine check.

The men, who are believed to be of Asian origin, are between 20 and 40 years old and should be in good health.

"They have been moved to a private passenger space on the ship and our employees focus on their well-being," Stena Line writes in a statement.

Have contacted the authorities

The company continues:

"Stena Line has notified Rosslare security and immigration authorities so that the necessary measures can be taken for the group when the ship arrives".

The news comes just a day after 25 freighters were discovered on a ferry between the Netherlands and Felixstowe in the UK.

Last month, 39 bodies were discovered in a truck space in Essex. All perished are suspected to be Vietnamese.