CON artists are trying to gouge hundreds of dollars from unsuspecting residents in a new fraud scheme which causes victims to rack up enormous phone bills as they attempt to claim huge cash and travel prizes.

The Police Commercial Crime Unit said it was unaware of the shakedown ? however, an e-mail is now circulating as a warning to residents.

The scam promises the "winner" exotic travel and spending money, and in some instances asks that they dial an overseas number to collect. The prefix falsely implies the calls are being made to and from Britain. Phone carriers in the United Kingdom are aware of the scam but unable to stop its progress. Even worse, victims have no means of seeking redress.

"Since the calls are originating from outside the UK, British Telecom and other telephone companies are left relatively powerless to act," the e-mail warns. "The only safe solution is to hang up before the message prompts you to dial 'nine' ? even safer, hang up on any unsolicited free offer calls."

Local fraud police said they were aware of similar schemes being run in the past and offered this advice as a blanket protection against all telephone scams.

"Always be wary of winning prizes and competitions for things that you haven't entered in the first place. It's often a ruse to initiate contact which will be the first stages of trying to get some money off you."

With these latest scams, initial contact is made by e-mail or telephone. Expenses amass as soon as the "lucky winner" makes an attempt to collect on the promised prize.

"(The) fraud applies to home and work telephones, landlines and mobiles," the warning continues. "If you receive one of these calls, upon answering the telephone you will hear a recorded message congratulating you on winning an all-expenses trip to an exotic location. You will then be asked to press 'nine' to hear further details.

"If you press 'nine', you will be connected to a premium rate line that costs approximately ?20 per minute. Even if you disconnect immediately, it will remain connected for a minimum of five minutes, costing around ?100.

"The final part of the call involves you being asked to key in your postcode and house number, which has other serious consequences. After a further two minutes, you will receive a message informing you that you are not one of the lucky winners."

A different version of the scam is used in targeting cell phones users. A missed call comes up, usually with the prefix 0709.

"If you call this number back, you will be charged about ?50 per minute. People have complained about their phone bills once they have realised the cost of the call, but apparently, this is completely legal. So beware, do not call back numbers beginning with 0709."

E-mail recipients are congratulated as one of six "lucky winners" to receive two air tickets for travel around the world and ?200,000 cash as part of an annual draw sponsored by an alleged British company, Phonework (UK). The message outlines three possible holiday routes and warns the person has 14 days to contact an appointed travel agent ? by e-mail, phone or fax ? to initiate plans.

When a supposed "winner" attempts to make contact with the agent by telephone or fax, a recorded message informs that their call cannot be connected and to try again later. The more attempts made, the greater the cost incurred.