Illegal immigrant arrests double at Dover port
The number of illegal immigrants arrested at the Port of Dover has almost doubled in two years, figures obtained by BBC Radio Kent show.
Between January and August 203 people were arrested entering Dover illegally, compared to 148 last year and 105 in 2012, the figures showed.
The port said the number of illegal immigrants crossing the channel needed to be "dealt with at source".
David Cameron said extra security had been given to the Calais authorities.
The figures obtained by the BBC under the Freedom of Information Act showed 139 people were arrested at the port in 2009. The following year the number fell to 119.
Mr Cameron said: "We need to take action right across the board and that has involved extra money for security at Calais.
"We have provided the security fence from the NATO conference for the authorities in Calais.
"We need full-hearted cooperation between the British and French authorities to make sure we can stop people getting on to trains, getting on to container lorries or other vehicles and coming across the channel."
Natalie Chapman, from the Freight Transport Association, said: "We don't know how many people have managed to get through without being detected.
"We don't know how successful the detection is, but clearly it does indicate there's a growing problem."
The Port of Dover said: "The recent immigration issues affecting Calais have caused a surge in the number of people attempting to reach the UK through the Port of Dover.
"The crisis at Calais is a matter of international concern, but is predominantly a matter to be dealt with at source."