An NSA contractor siphoned off dozens of hard drives' worth of data from government computers over two decades, prosecutors will allege on Friday.
The contractor, Harold T. Martin III, is also accused of stealing thousands of highly classified documents, computers, and other storage devices during his tenure at the agency.
It's not known exactly what Martin allegedly stole, but a report from The New York Times on Wednesday suggests that the recently leaked hacking tools used by the agency to conduct surveillance were among the stolen cache of files.
Prosecutors will on Friday charge Martin with violating the Espionage Act. If convicted, he could face 10 years in prison on each count.
The charges, news of which was first reported by The Washington Post, outline a far deeper case than first thought, compared to the felony theft and a lesser misdemeanor charge of removal and retention of classified information revealed in an unsealed indictment last month.
According to the Post citing a memo written by US Attorney Rod Rosenstein, the contractor presents a "high risk of flight, a risk to the nation, and to the physical safety of others".
The memo said that if he is released from custody, he "may have access to... a substantial amount of highly classified information, which he has flagrantly mishandled and could easily disseminate to others".
When reached on Thursday, a Justice Department spokesperson did not confirm the existence of the memo or comment on the story.