People are being warned to be aware of a scam involving telephone boxes in Bradford.

Offenders jam a cigarette butt into the coin slot, meaning the machine appears to have swallowed the money.

The coin actually remains in limbo without dropping into the coin box below and the person behind the scam returns later to retrieve the coins with a safety pin bent into a hook shape.

A man in his 70s was arrested for jamming coin slots with cigarette butts last year and Bradford's street wardens believe about four people are still using the tactic.

It is most commonly used in Bradford city centre, in areas such as Ivegate and John Street where phone boxes are well-used by members of the public.

Wardens regularly have to unblock phone box coin slots with Swiss Army knives before retrieving ill-fated coins with a piece of sticky paper.

With 30 phone boxes in Bradford, the scam is thought to be quite lucrative and can gain the offenders up to £5 an hour.