TRADING Standards has called for urgent action to crack down on bogus competitions that demand cash up-front, after a warning from a woman in Worcestershire.

The scams often start with letters, telephone calls or text messages telling the recipient they have won a prize.

One woman contacted Worcestershire Trading Standards after receiving half a dozen letters from different companies saying she had won cash prizes of up to £100,000.

But in order to claim such prizes people normally have to ring an expensive premium-rate phone line or send cash in advance to cover delivery.

Now the national Trading Standards Institute (TSI) warned that the ''prize'' rarely exists or is nothing like the description.

The body, which represents trading standards officials, believes one way to combat dodgy competitions is to limit the initial outlay winners are expected to pay.

"If consumers have genuinely won a prize they should not be asked to pay money to collect it," said Stuart Pudney, a spokesman for the TSI.

"In our view, there should be a legal maximum - say £1 - and anything more than that should be prohibited."

The concerns of the TSI were echoed by Citizens Advice, the umbrella charity for Citizens' Advice Bureaux.

"The best advice we can give is that people should not pay any money up front if they're told they have won a prize," said Teresa Perchard, policy director at Citizens Advice.

"So often there is not a prize and it's almost impossible to get your money back once you've paid.