Federal prosecutors now claim that former NSA contractor Harold Martin III’s theft of top-secret information was "breathtaking in its longevity and scale," directly contradicting initial claims that Russian hackers were responsible.

Dubbed the "second Snowden," 51-year-old Martin is currently facing charges from the US Department of Justice (DoJ) for mishandling classified documents, including the US government’s own hacking tools.

A Thursday court filing by prosecutors alleges that the former contractor collected several terabytes of internal data between 1996-2016. The DoJ may ultimately bring additional charges against Martin, including those under the Espionage Act.

"Given the nature of his offenses and knowledge of national secrets, he presents tremendous value to any foreign power that may wish to shelter him within or outside of the United States," prosecutors said.

A former US Navy veteran, Martin’s motives remain unclear. While he has been compared to whistleblower Edward Snowden, who revealed the extent of the NSA’s domestic spying apparatus, it appears that Martin’s activities predate Snowden’s.

US officials were quick to blame the Russian government for hacking into the NSA, despite the fact that early indications seemed to point to an insider.

"It appeared to me that because of the nature of the NSA network [that] it’s almost impossible to hack in. At least I don’t see how they could do it," former NSA whistleblower William Binney told Radio Sputnik’s Loud & Clear.

"So I assumed immediately that it was an insider."

Binney also points out that making baseless accusations against the Russian government for domestic problems feeds into the desire by the military-industrial complex to justify its size and continued growth.

"People have an interest to create, for example, a Cold War with the Russians. What that means is more trillions of dollars invested in the Defense Department and military-industrial complex and the intelligence complex."

It remains unclear how the unprecedented leak will affect US national security.

"The United States is engaged in defensive and offensive cyber activities, and any exposure of those activities is valuable information to everyone from our adversaries, to our allies, to privacy advocates, to courts, and anyone else who has an interest in US intelligence activities in the cyber realm," former federal cybercrime prosecutor Edward McAndrew told Radio Sputnik.

Martin’s defense attorneys argue that their client took the information from work so that he could improve his on-the-job skill set.