Thieves are targeting two specific models of car in Oxford, police said.

Det Sgt Matt Jarman said there had been a notable rise in thefts of older Vauxhall Corsas and Ford Fiestas since the start of the year.

Mr Jarman said the stolen cars have ranged from G registration plates — made in 1990 — to P plates from 1996.

The auto-crime officer said: “I think it’s a number of groups who have shared the knowledge of how to break into these cars and are doing their level best to steal them.

“In the process they are causing a great deal of heartache to the aggrieved.”

Det Sgt Jarman believed the two models had been targeted because their doors are easy to bend, which allows the thieves to get in to the vehicle.

As they were older cars they were also less likely to be equipped with alarms or immobilisers, he said.

Once inside, the vehicles the thieves have started the cars by inserting a screwdriver into the ignition, or hot wiring the car.

Thames Valley Police figures show since January 1, 13 Corsas and 12 Fiestas have been stolen in the city.

Det Sgt Jarman said in the main the Corsas had been taken from Cowley, Rose Hill and Headington, while the Fiestas had gone missing from Cowley, Headington and North Oxford.

Figures were not available for thefts of the same vehicles in the later months of 2008, but Mr Jarman said there had been a “notable rise”.

He said most of the cars had been recovered, but owners had faced the annoyance of being without their cars and negotiating with insurance companies over release fees.

Some of the thieves have also used the cars in bilkings — where drivers fill their cars with petrol but drive off without paying.

On other occasions the same models of car had been broken into and items stolen, which Det Sgt Jarman put down to the thieves not being able to start the car but grabbing any valuables before making off.