The Washington watchdog Judicial Watch has released 422 pages of FBI documents showing evidence of "cover-up" discussions related to Hillary Clinton's unauthorized email system within the company that managed it.

A Platte River Networks email sent in December 2014 says: "Its [sic] all part of the Hillary coverup operation I'll have to tell you about it at the party."

The documents obtained by Judicial Watch also show Intelligence Community Inspector General Charles McCullough forwarding "concerns" about classified information contained in the Clinton emails.

Judicial Watch also obtained Clinton's 2009 classified information Non-Disclosure Agreement bearing her signature.

And documents show Platte River Networks' use of BleachBit on the Clinton server to delete files. The program was downloaded on March 31, 2015, according to a computer event log. Over the next half hour it was used to delete the files on the server at a time when they were under subpoena.