A former NSA contractor, who has been in jail over charges of taking a massive horde of security material to his house, has agreed to plead guilty to the charge of illegal retention of information relating to US national security.
The charge to which he has agreed to enter a guilty plea could result in 10 years behind bars, according to reports in Politico and The New York Times.
The arrest of Harold Martin was announced in October 2016. He was working for Booz Allen Hamilton at the time of his arrest.
But the terms of the deal mean that Martin has no guarantee that he will not face 19 additional felony charges.
{loadposition sam08}He is expected to enter his plea on 22 January to one count of wilful retention of national security information connected with his taking home a single classified document.
This document is said to be "a March 2014 NSA leadership briefing outlining the development and future plans for a specific NSA organisation".
"The information contained within this document related to United States military and naval establishments and related activities of national preparedness, as well as the defence of the United States against its enemies," according to prosecutors.
Charges over 12 other NSA documents will remain in place.
There have been theories floated that Martin could be the source from whom the Shadow Brokers, an as-yet unidentified group, stole NSA exploits which they released on the Web in August 2016.
But equally, a third NSA ex-worker, Nghia Hoang Pho who pleaded guilty to taking national defence information home, is also suspected of being the Shadow Brokers' source.
Martin was a member of the Tailored Access Operations group of the NSA, an elite hacking unit, as was Pho.
After the leaks by NSA contractor Edward Snowden in 2013, three people are known to have been involved in unauthorised removal of NSA material from the agency.
One is Martin. The second, Pho, was, before his guilty plea, identified in the media as an unnamed software developer who was a Vietnamese American. He was taken into custody in 2015 after taking hacking tools home.
The third person, a woman named Reality Winner, was arrested after leaking a single NSA document to The Intercept this year.
Martin's lawyer, the federal public defender Jan Wyda, claimed at the first hearing in October 2016 that he was no traitor, only "a compulsive hoarder".