The Department of State recently discovered "thousands" of previously unreviewed documents that relate to Hillary Clinton and the Benghazi attack, according to a watchdog group that has been suing the department to release public records from Clinton’s tenure.

The State Department disclosed the existence of the additional records in a court filing on Friday and asked the judge for further time to search and review the documents.

The watchdog group Judicial Watch has been suing the State Department for years to turn over public records related to Clinton’s tenure as secretary of state, the Clinton Foundation, the employment arrangements of Clinton’s top aides, and her response to the Benghazi attack.

According to the State Department, the newly found records are likely to include information relevant to Judicial Watch’s requests. Officials said they would need until at least Feb. 1 to review the documents.

"After State filed its motion for summary judgment in this case [on November 11, 2015], State located additional sources of documents that originated within the Office of the Secretary that are reasonably likely to contain records responsive to Plaintiff’s request," said the State Department’s attorneys in a court filing.

A judge ordered the State Department to turn over public records after Judicial Watch filed a lawsuit against the department in September 2013. The case was reopened last year after it was reported that Clinton’s emails, which were sent over a personal email server, had not been searched.

According to Judicial Watch, Justice Department attorneys said the recently discovered documents include "‘working’ records in electronic format located on both ‘shared’ and ‘individual’ drives" that were used by individuals named in the watchdog group’s records requests.

Judicial Watch slammed the State Department in a statement on Monday, questioning why it took officials until now to find the newly disclosed documents.

"This latest find of Clinton records, at this late date, is astonishing," said Tom Fitton, Judicial Watch’s president. "The State Department waited to last possible moment, as it did with the Clinton emails, to tell Judicial Watch and the federal courts about thousands of records that haven’t been searched, as the law requires. Who knew what—and when did they know it—about these new Clinton documents?"

Fitton said the new records were a potential "game changer" and could be relevant to an ongoing FBI investigation into Clinton’s use of a private email server. Fox News reported on Monday that the FBI probe has expanded and is now examining potential connections between donations to the Clinton Foundation and contracts awarded by the State Department.

"These newly recovered Clinton records are a potential game changer—and will be of interest to the courts, Congress, and the FBI’s criminal investigation. It sure looks like more of the same in terms of Obama administration officials’ obstructing our FOIA requests, obstructing the courts, obstructing Congress, and obstructing justice," said Fitton.

In response to a separate lawsuit by Judicial Watch, the State Department said on Monday that it would review 29,000 pages of emails from Clinton’s top aide Huma Abedin for potential release, Politico reported.