Police have busted a phone line fraud operation wide open, arresting nine as part of an invesigation into a multi-million pound scheme.
The criminal plot is believed to have involved buying mobiles, many of which were iPhones, both in stores and online, using fake identities and counterfeit accounts.
SIM cards were removed and then placed in automatic dialing machines to make calls to premium rate numbers, which were run by the same criminal gang.
The City of London Police detectives, who had cooperated with O2 on the bust, believe the phones themselves were also sold on.
Regulation in some nations requires phone services in this case a fraudulent one to be paid by UK network providers before customers pay the operators.
This loophole meant the crooks received the money prior to O2 and other providers.
It was only when O2 approached its supposed customers, who were racking up monolithic bills, that the criminal activity was uncovered.
Today's operation saw eight men and one woman arrested on suspicion of conspiracy to defraud, following raids across England. One person is thought to be the mastermind behind the entire criminal operation.
Police also seized 15,000 worth of mobile phones still in their boxes but with the SIMs removed.
Laptops, computers, fake documents and thousands of pounds were recovered as well.
"We have struck at the very heart of a complex criminal network," said Detective Superintendent Bob Wishart, from the City of London Police.
"Our investigation found a crime gathering momentum. Each month more SIM cards were being used to make more phone calls to premium rate lines at more expense to the network provider."
Wishart noted how criminal gangs often use the latest technology as a basis for their activities.
"This was a sophisticated and organised attempt to defraud mobile phone operators," said Adrian Goreham, O2's general manager covering fraud and security.
"We are committed to reducing mobile phone crime and have a dedicated team that monitors and investigates such attempted criminal activity."
