Corrupt police used terror tactics to help reporters

The Metropolitan police will examine allegations that the News of the World paid policemen to track down targets using a method called "pinging", which involves bouncing a person's mobile phone signal from relay towers to locate their exact whereabouts. It is a tactic typically used by police or the intelligence services, with the help of network providers, to hunt dangerous criminals and terrorists and requires top-level clearance on a case-by-case basis.

The New York Times reported claims from a former showbiz reporter at the paper that corrupt officers helped a member of the newsdesk to track down a celebrity. The article claimed that the executive asked only for the person's mobile phone number and soon returned with an exact location in Scotland.

Oliver Crofton, director of cyber-security consultancy Vigilante Bespoke, said: "The phone company can easily identify which mast is the closest [to the phone], and then triangulate your location via the next closest two." But Mr Crofton, who advises celebrity clients on how to protect themselves against such methods, said it would be impossible for a "bedroom hacker" to get this kind of information without the assistance of the mobile phone provider – something only the police could legally obtain. Last week police launched Operation Elveden after News International emails appeared to show payments to serving officers.

A Met spokesman said: "Operation Elveden is an ongoing investigation into appropriate payments to police. We will examine all aspects and forms of police corruption deriving from inappropriate relationships with newspapers."