A US VoIP phone service kept one of the terrorists who carried out deadly attacks in Mumbai, India, in November in touch with his handlers based in Pakistan, according to reports describing a dossier of evidence compiled by Indian officials.
The dossier says handlers used a virtual phone number provided by service provider CallPhonex to call a cell phone used by one of the terrorists in Mumbai, according to printed reports.
"The controllers/handlers used the virtual number to contact a mobile telephone with one of the terrorists," the dossier says.
"This conversation was intercepted and, thereafter, all calls made through the virtual number were also intercepted and recorded."
The dossier does not describe whether authorities monitored the call via a tap on the wired portion of the network or by eavesdropping on the wireless leg of the connection.
CallPhonex could not be reached for comment.
The company can issue phone numbers from 35 countries. When the the numbers are dialed within those countries, there are no toll charges even though the party receiving the call is actually in another country. So in the case of the handlers, if they could call the terrorist using a local Pakistan number and be connected via CallPhonex's network to the terrorist's cell phone. The CallPhonex network can terminate calls with either VoIP, cell or traditional landline phones.
If the handlers were trying to call one of the terrorists on his cell phone, they would dial his Cellphonex-issued number and the Cellphonex network would bridge the call to the terrorist's cell phone number.
If the handlers had VoIP phones or softphones they could place the call from anywhere they could get an Internet connection.
According to a report in the online edition of Hindu Times of India, the account used was opened by someone using the name Kharak Singh, who identified himself as being in India. The Western Union transfer that paid for the service came from Pakistan, the report says, and was placed under the name Mohammed Ashfaq.
According to a report in the New York Times, the gunmen used Indian mobile phones to talk to their controllers, who gave them directions and kept them motivated.
CallPhonex describes its service this way: "Virtual phone numbers are normal geographical numbers, which can be called from anywhere, no matter where the caller is located, no matter whether it is from mobile phone or from a landline. Regardless of your location, parties wishing to reach you do so by simply dialing the local number."
The company has no virtual Indian phone numbers, but it does have Pakistani numbers. The company charges two cents per incoming call minute or sells flat-rate packages that come with a virtual phone number.