The number of people prosecuted for smuggling illegal immigrants into Britain in their vehicles has soared by more than 50% in a year, according to new figures.
Home Office statistics show that 88 people were prosecuted for sneaking stowaways into the UK in 2015/16 - far more than the 52 taken to court the year before.
The figures come amid mounting concern the migration crisis has driven larger numbers into the hands of people smugglers, risking their lives in the back of vans and lorries to make the dangerous journey to Britain.
Keith Vaz, chairman of the Home Affairs select committee, warned that many more people smugglers are going undetected.
He told the Press Association: "We welcome the increase in the number of prosecutions.
"However, based on the number of illegal immigrants who have entered the country this is only the tip of the iceberg and we need to be tougher on enforcement rather than what we have done before which is to send vans around telling people to leave the country.
"And it's vital that we send out a strong message to those who are smuggling people into this country that we will not tolerate such criminality.
"And the best way to do that is to increase not just the number of prosecutions, but the penalities of those who have been involved in smuggling."
The prosecution figures emerged in an answer to a parliamentary question asked by Labour MP Gareth Thomas.
It is not known how many illegal immigrants are living in the UK but a report produced by the LSE estimates there are between 417,000 and 863,000.
As hauliers and drivers have faced prosecution, there is growing evidence that people smugglers are increasingly turning to small boats and dinghies to ferry illegal immigrants to British shores.
In May, 18 migrants were discovered in a dinghy off the Kent coast near Folkestone
And the National Crime Agency - the UK's equivalent to the FBI - has warned criminal gangs have started targeting quieter ports on the east and south coast of Britain.
Meanwhile, there has also been a dramatic rise in the number of fines handed to employers for hiring illegal immigrants, with the number doubling in three years.
Some 2,594 were given in 2015/16 - more than double the 1,270 issued in 2012/13, although the figure is only slightly higher than the 2,339 given in 2009/10.