Police are warning Bradford residents to beware a fake telephone survey being used by burglars.

PC Martin Preston, of the Bingley-based Problem Orientated Policing (POP) team, revealed the ruse involved would-be thieves phoning people's homes and asking for information for a Post Office postcode questionnaire.

He said the scam, which has been prevalent in Derbyshire, resulted in 90 per cent of called homes being burgled within about a week of the call.

And he said callers were also promised a shopping voucher for taking part in the survey.

"It's something that people need to be aware of as lots of companies do carry out telephone surveys and people have to be careful not to give information to the wrong people," said PC Preston.

"The Post Office doesn't do postcode surveys and if anyone receives a call of this nature they should hang up and contact the police.

"It seems they ask for postcode details and try to engage the resident in conversation and before they know it they will have given them personal details, including the hours they are at work."

PC Preston revealed the scheme at the Cottingley neighbourhood forum meeting and said there were no examples in the Bradford area, yet.

"These sort of scams can move from area to area, like the Hanoi burglaries where burglars steal car keys and then steal the car, so it's best that people know about them before they happen," he said.

He said he heard about it through an internal police briefing.

A West Yorkshire Police spokesman said the information was being circulated to help raise awareness about the issue.

A Post Office spokesman said: "The Royal Mail and the Post Office never carry out surveys asking for postcodes when we already have this information."