Some 840 people have been caught at Dutch ports attempting to make the crossing to Britain this year, according to justice ministry figures.
Most of them were trapped trying to climb into lorries. Of the total, 43% were Albanian nationals, the figures show.
Hoek van Holland was the most popular location, with 450 stowaways. 180 were found in Europort and just 10 in IJmuiden. A further 190 people were picked up by British officials on the other side of the channel.
The ministry said the extra controls at Dutch ports which were introduced last year are now proving their worth. In 2015, police stopped 500 people trying to get into Britain.
