Former US Director of National Intelligence Dennis Blair accuses Edward Snowden of embellishing the facts and not being a "very credible witness."

Former Director of National Intelligence Dennis Blair
Former Director of National Intelligence Dennis Blair delivers a speech on \"the future of the US intelligence community\" to the U.S. Chamber of Commerce National Security Task Force in Washington July 22, 2009. (Credit: Reuters)

As investigations begin in the US as to just exactly how Edward Snowden was able to gain access to highly classified documents relating to the monitoring of US citizens, a former director of National Intelligence has called Snowden a "low-level employee" who is not a "very credible witness."

Denis Blair, who was Director of National Intelligence in 2009 and 2010 during President Obama's first term in office, told PBS News: "Clearly [Snowden] did not have the full picture of these programmes which are run by the intelligence agencies."

Blair added that Snowden seemed to be embellishing what he knows as a "low level employee," who was unaware of the checks and balances in place in the wider programme.

Blair has also written an opinion piece for the non-profit organisation Freedom House - where he is a board member - in which he categorically denies media reports of widespread monitoring of US citizens' online activity or phone calls:

Reasonable suspicion

"As a former director of national intelligence, I was directly involved in these issues, and can state unequivocally that the only conditions under which the national intelligence agencies gather any information about Americans is when the court established by the Foreign Intelligence Surveillance Act (FISA) has given permission, based on a reasonable suspicion that the American is involved in terrorist activity."

Blair goes on to address the somewhat disparate positions he holds as a former US intelligence chief and as a board member with Freedom House, which is an independent watchdog group "dedicated to the expansion of freedom" around the world.

Blair says: "Freedom House is rightly concerned about authoritarian governments' surveillance of their citizens' communications for the purposes of repressing free speech, political discussion, and civil society advocacy.

"The system in the United States, based on the principle of limiting the gathering of intelligence on Americans by statute, by the decisions and supervision of an independent judiciary, and by an inquisitive and independent press, is a model for balancing the responsibility of a government to protect its citizens with their rights to privacy and liberty."

Investigation begins

In the US, officials in the intelligence community are now working on figuring out just how a employee of a contractor (Booz Allen Hamilton) was able to access such sensitive information and take it outside the system - considering he was based at a satellite office in Hawaii dealing with the monitoring of foreign threats not US based threats.

According to officials speaking to the Washington Post, only 30 or 40 people would have had clearance to view the sealed court order from the Foreign Intelligences Services Court (FISC) which gave the NSA the freedom to monitor the metadata from over 100 million Verizon customers in the US, which Snowden was able to access and subsequently leaked to the Guardian.

Snowden's current location is not known, having reportedly fled the luxury hotel he was staying in in Hong Kong since arriving there on a flight from Hawaii on 20 May.

Investigators are working to build a case against Snowden, separately from his admissions on video in an interview with the Guardian on Sunday, and they are further trying to establish if he was working with someone else, or on his own.