FRAUDSTERS operating on the internet are sometimes swindling people out of thousands of pounds, police warned today.

Posing as buyers, the con artists target victims who advertise items for sale on legitimate websites.

A Gwent Police spokeswoman said they contact the seller and send, or offer to send, a cheque for a much higher price than the item has been advertised for. They ask to victim to send a cheque for a smaller amount and the item to an address, often abroad.

They later discover that the buyer's cheque has been stolen and cannot be cashed or is drawn on an account with insufficient funds.

Gary Probert, hi-tech crime investigator with the Gwent force, urged people to be on their guard.

"Victims of these scams can lose thousands of pounds. Some people are taken in by the fraudsters who think they can get money for nothing. "My advice is: if it sounds too good to be true then it usually is."

He added the scam had been around for some time - it was particularly popular a couple of years ago - and reported incidents had become more frequent again recently.

He also warned people to be wary of dealing with web-based email accounts. "Many of these fraudsters are difficult to trace as most use internet-based email accounts which are often set up with false details.

"I would also urge people to call police if they are asked to part with money or give bank details over the internet."