Critics of the UK’s soft-touch immigration system said the figures exposed a culture of complacency from those in charge of security.
The figures come after five Iranians were caught entering Britain illegally, arrested and told to “report in regularly”.
The men landed on the beach in Winchelsea, East Sussex on Sunday, and after arrest Border Force officials let them go while their cases are “progressed”.
The incident, revealed exclusively by the Daily Express yesterday, has prompted calls for an immediate investigation.
Ukip leadership candidate Bill Etheridge said: “We have had the brutal murder of someone in London with terrorist links still not ruled out, yet we let people from an Islamic country wander up the beach and into the sunset.