If they can't get the right dogs it is the police's fault not the dogs', because they are wanting them on the cheap

Dr Malcolm Willis canine geneticist

Speaking to the Police Review magazine, he said: "German shepherds have had the suspicion and boldness bred out of them.

"Dog shows don't look for aggression but for dogs which look nice and which are subdued. But working dogs need to be alert."

His concerns were backed by Hampshire-based Inspector Howard Norman, who told BBC Radio 4's Today programme: "They have gone soft, the quality is not the same as 20 years ago."

He said his force was travelling to the Continent to find alternatives.

German shepherd's "too soft"

It was looking at the Belgian Malinois which is similar to the German shepherd but smaller.

But dog breeders are amazed by the police move.

Phil Buckley of the Kennel Club said breed standards had not changed.

German shepherds were bred to be "steady of nerve, self-assured, courageous and tractable, never nervous, overly-aggressive or shy".

And Newcastle University canine geneticist Dr Malcolm Willis - also chairman of the German Shepherd Dog Breed Council - told the Today programme the German shepherd was ideal for police work.

Breed has polarised

"If they can't get the right dogs it is the police's fault not the dogs because they are wanting them on the cheap."

He said police should breed their own rather than rely on dogs being donated by the public.

"Breeders are not setting out to breed a police dog, but to breed a companion animal.

"People don't want to sell animals that could have a kiddie's hand off."

He said the charity Guide Dogs for the Blind bred their own animals with a 90% success rate.

'Proper breeding'

Maureen Paul produces 20 German shepherds a year for the police from kennels in Berkshire.

She agreed that non-specialist breeders were producing animals that were unsuitable for police work.

"The breed has polarised into two different factions - the traditional English bloodline which is now much too docile and the German bloodline which is too hyped up and difficult to control.

"There is nothing to equal the German shepherd if it is properly bred."

German shepherds are the UK's second most popular dog with 18,000 registered with the Kennel Club last year.