Throughout Europe, hackers are breaking into corporate telephone systems and making calls. Insiders estimate the cost so far to be at least £45.5m.

In the past telephone system hackers, or phone phreakers, were more prominent, especially in the era of Cap'n Crunch, who started it all.

Most systems involved are Meridian 1 systems manufactured by Nortel and supplied and serviced by Kapsch. In one case telecommunications equipment from Ericsson was involved. Ericsson has confirmed the incident.

The hackers are said to have gained access to the telephone systems by breaking into a GSM (the European mobile phone standard) gateway, which determines the best rate for calls between mobile phones. Calls were made to Thailand, Saudi-Arabia and Iran.