Known as photophone, the device enables officers to discover the identity and previous records of suspected fans within seconds.

Police spotters in the crowd around Wembley and known troublespots will photograph individuals they are suspicious of with a digital camera.

The camera then sends the picture by mobile phone to the London headquarters of the National Criminal Intelligence Service where it is checked with the database of all known football hooligans.

If a match is found, the thug's criminal record and full details including any court orders preventing him or her from attending football matches are automatically sent back down the telephone line to the waiting police team on the ground.

Deputy Assistant Commissioner Michael Todd of the Metropolitan Police said known troublemakers would be spotted if they decided to attend the match and officers would act if they "start to misbehave".

The system was also deployed as part of the security operation on Saturday when England beat Scotland 2-0 at Hampden Park, Glasgow in the first round of the tie.

Bad old days

Police are out in force to prevent London witnessing a return to the bad old days when Scotland- England ties were dogged by violence.

Undercover officers are on the alert and trained spotters are on duty at London stations and airports and are travelling with fans.

Police will monitor flashpoints

Police will also be monitoring potential troublespots such as Trafalgar Square and Leicester Square. Most of the violence following the game at Hampden Park happened in Glasgow city centre where fans had been watching the game on television.

A similar surveillance system that can automatically pin-point known criminals as they walk along in a crowd is being tested in the east London borough of Newham.

The Mandrake face recognition system seeks out "target faces" from 140 closed circuit television (CCTV) sites.

According to Newham, crime has dropped by 70% since the system was introduced.

A private system - at Liberty in Regent Street London - was launched earlier this year and another is set to follow at Tower Records in Piccadilly.