THE police force covering England's largest county is looking to spend almost £m on expanding a scheme to "fast track" the detection of travelling criminals dealing in hard drugs and stolen property.

Police in North Yorkshire already have nine cars and one van equipped with mobile automatic number plate recognition, which works by having special cameras either at the roadside or on overbridges.

The cameras instantly scan the number plates of vehicles as they pass and match them against information stored in computer databases to identify stolen cars or those suspected of being involved in crime.

When a suspicious vehicle is recognised, the computer transmits the "hit" to the operator of the equipment so that immediate action can be taken.

The North Yorkshire force has a dedicated team of one sergeant and five constables operating the equipment who, the controlling police authority heard on Monday, made 363 arrests and recovered more than £400,000 worth of stolen property and illegal drugs last year.

Now the force wants to extend the system to incorporate 12 cameras at three fixed sites on major roads across the county, the exact locations of which are not being revealed for operational reasons.

Assistant chief constable Peter Bagshaw assured the authority that recent public speculation about possible sites was incorrect.

Authority members heard that a recent road upgrade at one of the proposed sites meant that coverage with mobile equipment was no longer possible. A fixed site would allow interceptions to continue on that route, which had proved highly productive in arrests and recovery of stolen property and drugs.

Fixed sites would increase the capability of the force to target persistent and prolific offenders and travelling criminals including those dealing in such hard drugs as cocaine and heroin.

Mr Bagshaw said the North Yorkshire force had been promised £200,000 by the Home Office, through the 2004 spending review, to help develop the fixed sites. The bid had been submitted after consultation with neighbouring forces to ensure that maximum regional coverage was achieved without duplication of effort.

To complete the system at a total cost of £450,000, including upgrading of computer equipment, the authority would need to apply for £250,000 from an investment fund run by the police authority.

The application was approved on Monday by the strategic planning and best value board of the authority.

Mr Bagshaw said annual costs of about £60,000 for maintenance of equipment and rental of telephone lines would be met from existing police budgets.

He added: "Fixed sites will enable us to check about a million vehicles every 24 hours."