Last updated at 14:41 13 May 2008

Underage drinkers attempting to buy alcohol could soon be thwarted by cutting edge technology currently used by police to identify suspected criminals.

A supermarket chain is introducing face recognition cameras in a bid to prevent staff mistakenly selling cigarettes and booze to children.

The biometric technology, which helps identify underage customers, is being piloted by Budgens at one of their London branches.

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Face recognition: Will be used to stop underage drinkers buying alcohol

If successful, it could be rolled out across the country to create a giant database of customers.

The system, which has customers facial images stored on a database, immediately alerts a cashier if it recognises someone who has previously been unable to prove they are 18.

Once aware, staff can carry out the proper checks.

In the future, images of offenders could be pooled with other convenience stores, allowing retailers in an area to instantly know if a customer is under-age.

It is believed to be the first time a British retailer has used the technology to identify underage customers.

But critics say the storage of such sensitive data could infringe customers' civil liberties.

The facial recognition software takes measurements between key points on the face, making a unique template of a person's features.

Budgens have installed three cameras at the pilot branch, one at each till.

They monitor customers as they approach the checkout lanes and relays their image back to a control centre in Worcester.

Customers' scanned facial features are then compared against a database of under-18s who have previously visited the store. Anyone refused alcohol or cigarettes in the past will be automatically flagged up.

The system also identifies customers who have previously verified their age, allowing them to be served more quickly.

To comply with the Data Protection Act, the system stores the information as data or 'tokens' - which cannot be reversed back into images, but can be compared to fresh pictures.

Currently 1,500 'tokens' are stored on the database, says Charlie Willetts, managing director of Charton Ltd, which is supplying the software.

With the system capable of holding up to two million sets of data, Mr Willetts said other retailers were interested in linking the scheme to their own shops to create a giant database of customers.

He said: "This is the first store in the country doing this, but we have had great interest from retailers looking to install the technology."

Police and other law enforcement agencies use face recognition technology to match CCTV footage of suspects with a database of known offenders.

Trials will also begin in the summer at British airports to scan the facial details of some passport-holders, in a bid to improve the fight against ID fraud.

Hi-tech gates will scan people's faces and compare the image with their biometric passports. If the pilot scheme is a success, the technology will be rolled out to airports and seaports nationwide.

The trial will initially be for British and EU citizens carrying the new biometric passports. It is not clear how many airports will take part.