A thumbprint scheme to cut credit card fraud has proved a big success in its first year, police said today.

Introduced into Bradford city centre shops and garages last spring, the scheme has gradually spread and now 35 outlets have taken it up.

"It has worked well," said Bradford South crime Prevention Officer Mick Warburton. "Feedback from all the stores shows that it is acting as a deterrent to crooks, which is its main purpose."

At participating shops, customers are asked to supply a thumbprint in black gel on the back of their cheque or credit card slip. The gel rubs off the fingers easily.

If the credit card used then turns out to be stolen or cloned the print is used to find the fraudster. Otherwise it is destroyed.

"Criminals respond to the stickers in stores explaining the scheme," said PC Warburton. "They don't go in there. Quite apart from the chances of being caught through the thumbprints, they know that these stores are switched on about security in general."

At Bradford's Kirkgate Centre, security chief Mirco Maric said the stores using the thumbprint pads had seen a definite benefit.

"We would like to see more outlets taking part all over Bradford," he said. "The public have reacted well. There is perhaps one shopper out of thousands and thousands who does not wish to give a thumbprint.

"Most people are happy about it once the system has been explained to them. We will keep trying to get people to come on board."

There is no compulsion to give a thumbprint, said PC Warburton. But stores will ask for some other form of identification, such as a driving licence, to back-up a credit card. And he stressed that no thumbprints are passed on to the police or kept by the stores unless a fraud has been committed.

At fashion store To Die For, manager Josey Baldacchino said: "There has been a downturn in card fraud. It has gone very well.

"You do have to be prepared to explain to customers, but they appreciate that if they have nothing to hide there is nothing to fear."

PC Warburton said that chain store managers in Bradford have said they would take part if they could persuade their head offices.

Some chains fear that asking customers to provide prints might harm their image but, he said, the experience so far had been that many shoppers prefer to go to shops using the scheme because they feel safer there.

Several stores say that they actually get increased sales because customers have more confidence in the security.