Twelve Vietnamese stowaways were caught trying to enter Britain illegally last month, the British Embassy in Hanoi said Wednesday.
The stowaways were discovered at the port of Calais in France during routine lorry inspections as the vehicles were preparing to cross the English Channel to Dover, an embassy press release said.
The first group of six was discovered by UK Border Agency officers on July 16, when they were hiding inside a Netherlands registered vehicle carrying a load bound for Scotland.
On July 21, a further six Vietnamese stowaways, including two women, were found hiding inside a Polish-registered lorry load of garbage bins.
The 12 Vietnamese have been handed over to French Border Police, and the vehicles were allowed to continue their journey to the UK.
However, both the drivers and the haulage companies involved now face potential fines if they are unable to prove they took steps to secure their vehicles.
Antony Stokes, British Ambassador to Vietnam, said: "The UK welcomes Vietnamese visitors, including Vietnamese students to the UK. But entering the UK clandestinely without a visa is both illegal and dangerous.
"We encourage all Vietnamese to go through the right channels to enter.
"Those who don't are putting their lives at risk."
According to the UK Border Agency, in 2010, its officers carried out 1.5 million traffic checks, stopping more than 9,700 attempts to cross the channel illegally down from 29,000 in 2009.