(Silicon) Gatwick airport is the latest UK airport to trial biometric fingerprinting technology to boost immigration security.
The BioDev pilot has been running in the airport's North Terminal since 18 September and is due to end in April next year.
At present only arrivals from Sierra Leone who have been issued with biometric visas in the capital Freetown will be included in the trial.
A Home Office spokeswoman explained that Sierra Leone was chosen because the main flight into Gatwick from the country arrives at a quiet time with a low number of passengers. This makes it logistically easier for immigration staff to trial the tech. In addition, citizens of Sierra Leone require visas to enter the UK.
On arrival, passengers will have their fingerprints and photos checked against a database by immigration officials, and those attempting illegal entry into the UK will be refused entry.
The project is part of an overhaul of the UK's border security. UKvisas, a joint Home Office and Foreign and Commonwealth Office unit that runs the UK's visa service, is already collecting fingerprints from visa applicants in more than 100 countries around the world.
The aim is to stamp out multiple visa applications and identity fraud.
Immigration minister Liam Byrne said fingerprint visas are fast becoming "our first line in defence against illegal immigration" as they establish people's identities "beyond doubt" before they enter the UK.
Byrne added biometrics are part of a triple ring of security for the UK's borders, which involves identifying individuals before they travel to the UK, checking them on the border and rolling out ID cards for foreign nationals in the UK from 2008.
The Border and Immigration Agency is aiming to use biometric measures for all non-visa nationals arriving from outside the European Economic Area by 2011.
As part of this, the Home Office recently spent $4.4m on new fingerprint scanners to be used in embassies around the world.