THE number of Telstra customers caught in an apparent phone scam has snowballed, with at least 60 homes and businesses in the Merewether area now affected.
More than 50 people with numbers starting with 4963 contacted the Newcastle Herald yesterday to say they had received bills listing calls to 1900 information numbers, which they had not made.
The most commonly listed number on the bills was 1900 910 080, which is charged at a flat rate of $13.97.
The number is administered by the international information service provider Cloudtel.com and is linked to the European-based gaming website runescape.com.
Telstra is continuing to investigate how the numbers were accessed.
A telecommunications engineer told the Herald it was possible that those who had their numbers used were victims of caller ID-spoofing technology.
"I would say that someone has set up a server somewhere along the line that makes phone calls pretending to be certain numbers," he said.
The server provides the fake number to the next switch or gateway on the signal path.
"If it is an interconnected switch it probably won't know that that number is not who it says it is," the technician said.
He said it would be difficult to tell if the calls were originating in Australia.
"They have taken a few steps to make it look as local as possible. Where they may have tripped up is forgetting that we are in a different time zone and most people don't make calls like that at 2am."
Telstra Hunter region general manager Chris Cusack refused to speculate on what may have caused the unauthorised access to the numbers.
"There could be a range of explanations for what has happened," Mr Cusack said.
"It would be premature to suggest it is a scam."
He urged customers with bills listing calls to 1900 numbers, which they had not made, to contact Telstra on 132 200. The telco has reimbursed the majority of those who have been wrongly billed for accessing 1900 services.
One customer, Renee Radford, said she had spent three weeks trying to resolve the matter with Telstra.
"It was incredibly frustrating. I was dealing with people in overseas call centres who kept on telling me I must have made the calls," Ms Radford, who received a bill listing $150 worth of calls to 1900 numbers, said.
Consumers who are unable to resolve the matter can make a complaint to the Telecommunications Industry Ombudsman.