Learning English and exploring the architecture of Bradford at night are just two of the excuses used by kerb crawlers to explain why they were driving around the city's red-light district.

Under a new partnership between Bradford Council's anti-social behaviour unit and Bradford Police's vice squad, letters are being sent to vehicle owners spotted driving suspiciously in Listerhills Road, Sunbridge Road and Thornton Road.

They are being asked to explain their behaviour in a bid to shame kerb crawlers and try to stamp out Bradford's vice trade.

Detective Inspector John Armitage, of Bradford South CID, said many of the excuses given to vice squad officers were "unbelievable".

He said any driver without a legitimate excuse would be shamed in court but law-abiding drivers had nothing to fear.

"One of the strangest excuses we've had is from somebody who said they were looking for somebody to teach them English as they weren't fluent in the language," he said.

"Another gentleman said he was interested in old buildings and therefore he liked to drive round and look at the interesting buildings in the red-light district at ten at night.

"Another well-used excuse involves a person saying their wife or partner is at some kind of evening class and they are driving around the area killing time until they pick them up."

As revealed in the Telegraph & Argus yesterday, for the first time Bradford Council is issuing "acceptable behaviour contracts" to people caught seeking prostitutes on the city's streets.

Det Insp Armitage said letters were being sent to all registered owners of the vehicles, including businesses.

"The purpose is to allow the owners to explain what they were doing in the area at that time," he said.

"Obviously it gives them a chance to explain if they had a legitimate reason for being there so their names don't have to be put on our kerb crawling database."

Kerb crawlers who breach the acceptable behaviour contracts will have anti-social behaviour orders sought against them in the courts to ban them from the city.

Any breaches of those orders could lead to up to five years in jail.

Four acceptable behaviour contracts have already been issued to drivers in the first stages of the partnership and further operations are planned.