Police in Bradford are using hi-tech computers to pick up suspects who pretend they are someone else.

Officers in the district have been issued with pocket-sized BlackBerry computers which can instantly download digital mugshots of people on police systems.

The devices are helping police outwit suspects on the wanted list who try to bluff their way out of being arrested when they are on the street.

When officers stop someone they believe is wanted for an offence they have to confirm the person's identity.

But many try to trick their way out of arrest by providing false details, often of someone they know who is not wanted by police.

Now, police can instantly see that the suspect is not who they say they are. If there is an outstanding warrant for them it will show on the screen and the warrant system can be accessed.

The technology, a mobile version of West Yorkshire Pol-ice's main computerised intelligence system, has already led to a number of arrests.

The force's information systems director Paul Friday said the development followed an internal survey to find out what extras officers would like from their BlackBerrys to help them in their job.

The StreetWYSE BlackBerry contains every piece of information the force has on individuals, as well as comprehensive information stored on the Police National Computer.

As well as being able to access images, the system allows officers to discreetly use the device to check other vital information, such as whether someone stopped is known to carry weapons or be violent to police.

Officers can have their daily briefing information sent to their BlackBerry on e-mail.

There are links to local intelligence records.

West Yorkshire Police has 2,500 BlackBerrys in use, nearly all of them with front-line officers.

They were bought for £1.5m, including airtime.

Training on the StreetWYSE system takes a matter of minutes. But BlackBerrys have saved the force an estimated £8.8m in time saved in officers accessing computer systems while on the streets - an average of 145 hours per front-line officer per year.