Following the enforcement teams at Heathrow Terminal 3, Calais, Dover.

At Heathrow's Terminal Three, officers stop a student from entering the UK after a trip home to his native India, while the team in Calais search lorries they suspect are being used to smuggle illegal immigrants.

Excess baggage in the form of six undocumented immigrants is coming in from Calais.

Following the enforcement teams at Heathrow Terminal 3, Calais, Dover.

Cameras gain access to the British Commission in Lagos, Nigeria, a city with a strong reputation for fraud; staff at a West London steakhouse are grilled in the search for illegal immigrants.