Officers in Calais search lorries for illegal immigrants, while at Heathrow Terminal 3, a student is prevented from entering the UK after a trip home to his native India.

New documentary series taking viewers inside the UK Border Agency, revealing the work that takes place behind the scenes of the immigration process. Teams at Heathrow Terminal Three, Calais, Dover and across the North West and North East of England reveal the methods and technology used to allow legitimate visitors safe passage while catching those who try to gain illegal entry to the UK.

Officers at Heathrow Terminal Three question a passenger from Johannesburg arriving in London on a tourist visa, suspecting he may actually be coming to work in the country. Entry Clearance Officer Dan Brown, on secondment to the British High Commission in Delhi, encounters a man carrying false identity documents - an arrestable offence.

Immigration officers at Heathrow's Terminal Three investigate a Jamaican man they suspect is a drugs mule after a suspicious x-ray examination. At a London Underground station, a suspected illegal immigrant tries to run from officers, but his escape is hindered by a member of the public.

Officers search UK-bound lorries and discover illegal immigrants during rush hour at Calais, while in the UK police target illegal workers as they raid a chicken factory.

Documentary series taking viewers inside the UK Border Agency, revealing the work that takes place behind the scenes of the immigration process. Teams at Heathrow Terminal 3, Calais, Dover and across the North West and North East of England reveal the methods and technology used to allow legitimate visitors safe passage while catching those who try to gain illegal entry to the UK.

Documentary series taking viewers inside the UK Border Agency, revealing the work that takes place behind the scenes of the immigration process. Teams at Heathrow Terminal 3, Calais, Dover and across the North West and North East of England reveal the methods and technology used to allow legitimate visitors safe passage while catching those who try to gain illegal entry to the UK.

The Manchester enforcement team conducts raids in Rochdale, searching for illegal workers, and a man is deported to Nigeria. Last in the series.