The British Newspaper claims the second largest US operator has been providing the NSA with information on all domestic and international telephone calls in its system, following a top secret court order issued in April.
Under the terms of the order, Verizon is said to have been handing over the phone numbers of both parties in a call and their locations, as well as the time and length of the call.
The contents of the conversation, however, are not covered.
The communication records of millions of US citizens are said to be collected indiscriminately and in bulk, regardless of whether or not they were under suspicion of wrongdoing.
It is unknown whether Verizon is the only mobile operator to be targeted in the order, or whether the NSA has been granted access to the networks of other major US mobile operators.
This is the first time the Obama administration has allegedly been found to be monitoring the communications of US citizens in bulk, and is likely to reignite major concerns about privacy in the US market.
It was reported that former president George W. Bush authorised NSA monitoring programmes on phone, internet and emails shortly after the September 11 attacks.
