THOUSANDS of web surfers in York and North Yorkshire could be unwittingly forking out for premium rate phone calls in a worldwide computer scam.

Harold George, of Main Road, Hambleton, near Selby, contacted the Evening Press after calls worth £50 mysteriously appeared on his bill.

The three short calls, which Mr George says he never made, were to the remote African island of Sao Tome.

His internet service provider, AOL, told him it was possible that an automatic dialler had been planted on the computer without his knowledge.

This would dial up numbers and run up large bills without the computer user doing anything.

Mr George, 57, said: "I think it's absolutely outrageous. If somehow calls are being made from my phone, and running up my bill, then that is theft, pure and simple.

"Someone is taking money for nothing from me, but apparently no one knows who they are. It should definitely be illegal, if it isn't already."

Both AOL and BT have launched investigations into the incident. Mr George does not blame either of them for what happened.

The Evening Press has also been made aware of a York case in which automatic dialling cost a family £50.

The family's internet service provider told them someone with access to their computer must have logged on to the automatic dialler, but none of the household remembered doing any such thing.

The baffled householders ended up having to settle their unwelcome phone bill.

York computer expert Anthony Dodd, who runs Aurora Technical Services, said web users can sometimes install diallers without realising it.

"Some sites will say that in order to access our site you have to use our software," he said.

Rob Dwight, of premium rate line watchdog Icstis, said that if a dialler was added without a computer owner's knowledge, the company adding it had committed a fraud.

Mr Dwight said: "We can then take action if the victim contacts us. We recently clobbered one premium rate service provider with a £75,000 fine, barred access to their service and ordered them to repay money to their victims."

A spokeswoman for AOL said it was "very easy" to accept a dialler.

She said: "It can be done by unknowingly clicking on a link on a website or popup, thereby accepting the terms and conditions."

Avoid the con:

Anthony Dodd's advice if mysterious call charges appear on your bill:

Regularly check your dial up network settings.

Make sure nothing unrecognisable is listed.

Install lavasoft ad-aware, a free for personal use protective programme, available for download from www.lavasoft.nu

Updated: 10:28 Wednesday, April 14, 2004