Haulage firms and lorry drivers have been fined more than £4 million after migrants were found in their vehicles - with the number of fines up 50 per cent on last year.
More than 3,300 fines were issued by UK Border Force staff in 2014-15, up from 2,177 in 2013-14, according to BBC News.
The fines can reportedly be as much £2,000 per migrant and can be levied against both drivers and their employers.
Hauliers told BBC News they believe the system is 'unfair', but the Home Office said many lorries did not have 'basic standards of security'.
The fines, known as civil penalties, can be imposed as lorries enter the UK, and also when they are searched by UK officials at ports in France - such as Calais - and Belgium, under the so-called juxtaposed controls system.
The figures come amid the crisis around Calais, during which thousands of migrants have tried to board UK-bound lorries.
