POLICE believe the same gang is responsible for a spate of thefts of catalytic converters in Oxfordshire.

Since the beginning of May, 23 of the pollution-reducing devices have been taken by crooks armed with cutting equipment from vehicles across the county, costing car owners thousands of pounds in repairs and increased premiums.

The only other report of a similar theft in Oxfordshire this year was in February, although the Oxford Mail reported on a three-month series of thefts of catalytic converters in May 2008.

Officers believe the catalytic converters, which filter emissions from exhaust pipes, are being exported overseas to be sold as scrap metal, particularly for the platinum they contain.

Pc Phil Marstin, of West Oxfordshire Auto Crime Team, said the devices could be sold for about £70.

He said: “It is distinctly possible that there are more victims out there that we don’t know about.

“Having 23 stolen in the past seven weeks is a massive percentage increase in terms of catalytic converter thefts. Someone has the idea and is maximizing the opportunity.”

Pc Marstin said he believed the same gang of “brazen” thieves have been targeting long-stay car parks, mainly in Oxford, Banbury and Witney.

He said: “The turn-over of long-stay car parks is very low. You don’t get people coming back to their cars very often so there is the opportunity to get away with it.

“Alarms usually go off only if the car’s interior is tampered with.”

It is thought hydraulic cutters or hand-held disc cutters are used to remove the catalytic converters, a manoeuvre which can be done in about 40 seconds.

Many 4x4s, people carriers and small vans have been targeted, as their height makes the exhausts easier to access.

Pc Marstin urged people across the county to report suspicious activity.

He said: “People end up paying for the damage themselves as the long-term effect on their insurance is more expensive than paying the bill.”

David Williams, manager of Witney Tyre and Exhaust, in Thorney Leys, said it could cost up to £900 to replace a catalytic converter.

He said: “You can’t drive a car without one.”

Jan Bone, 57, parked her car in the long-stay car park near Waitrose, in Witney.

She believes thieves used a hydraulic cutter to remove her catalytic converter on June 9.

Two other cars were targetted in the same car park that day.

Mother-of-two Mrs Bone, of Bampton, had to pay £1,250 for parts and labour. She claimed it on her insurance but says this will now cost her more in increased premiums.

She said: “It’s a massive inconvenience. I initially drove my car away wondering why it was making such a noise.

“I had to drive it for a couple of days at least to get to work, but I probably did damage to the car by doing that. In the future I will be extra vigilant.”