Mobile phone theft in Oxfordshire is likely to fall dramatically because of new measures which render stolen handsets useless.

Theft of mobiles has been on the increase across the county -- with many stolen to pay for drugs.

But most offenders will now find it impossible to use or sell a stolen phone because the handset will be barred across all networks, after phone companies agreed to a shared database.

Previously, phones which were barred on the victim's network could be reprogrammed legally with a new identity number and re-used.

However, it was made illegal to reprogramme mobiles earlier this month. Anyone doing so now faces five years in prison.

There were 4,935 phones stolen across the county in the year to September 30 -- about 1,200 more than during the same 12-month period in 2000-2001. Most thefts -- 2,904 -- were in Oxford, an increase of 500.

Det Sgt Ian Holt, Thames Valley Police crime reduction officer, said: "It will make stolen mobile phones useless and of no value to potential thieves or robbers. This should reduce the incentive to want to steal them in the first place."

The new measures were welcomed by Mike Simm, head of Oxfordshire Youth Offending Team, which strives to stop repeat offending among young people. Many victims of phone theft are teenagers.

He said: "I would absolutely welcome this. Mobile phones are a status symbol, and are easily stolen and reprogrammed. Anything that makes them less attractive is almost certain to lead to a reduction in theft."

Bill Holman, co-ordinator of Oxfordshire Drug and Alcohol Action Team, welcomed the initiative, but felt some offenders might turn to other crime to pay for drugs.

The minimum sentence for mobile phone theft is 18 months -- with sentences of up to five years for the most violent incidents.

Crime reduction officers urge people to have their phones marked with ink which shows up under ultraviolet light.

Spokesman for mobile phone network O, Simon Gordon, welcomed the initiative, but said research showed only 20 per cent of stolen mobile phones were re-used. He said some went overseas and were stripped down for their components.

He said O was working with police and councils to reduce mobile phone theft through other measures, such as phone-marking.

In the year to September 30, 1,197 handsets were stolen in southern Oxfordshire. In northern Oxfordshire, 834 were taken.

Anyone with information should call police on 01865 846000 or Crimestoppers on 0800 555111.