Oxford's dog warden is warning owners to beware of the growing national trend of dog theft.

Dog warden Jenny Bromley with Barney

Jenny Bromley, the dog warden service manager for the city council, said there had been about 20 cases in Oxfordshire in recent years.

Mrs Bromley said stolen dogs could be sold for sporting purposes.

She said: "One particularly worrying development is thieves waiting until owners offer a reward for information on posters and then demanding a ransom of several hundred pounds, before returning the pet."

Two years ago, Mrs Bromley set up an e-mail exchange system called Dogwatch. It allows 35 local authorities across the country to share information about missing dogs.

Anyone wanting to report a stolen dog should call Mrs Bromley on 01865 467291.