Hillary Clinton turned over about 54,000 pages of messages at State’s request in December 2014. | Getty

A federal appeals court has revived a pair of lawsuits seeking to force the federal government to sue former Democratic presidential candidate Hillary Clinton in a quest to try to recover more emails from the private server she used while secretary of state.

A three-judge panel of the District of Columbia Circuit Court of Appeals ruled unanimously Tuesday that a lower court judge erred when he threw out the cases as moot after the State Department received tens of thousands of emails from Clinton and more from the FBI following the criminal investigation it conducted.

Watchdog groups Judicial Watch and Cause of Action filed separate suits in 2015, asking that Secretary of State John Kerry and the head of the National Archives, Archivist David Ferriero, be required to refer the Clinton email issue to the Justice Department to consider filing a civil suit to get missing federal records back.

D.C. Circuit Judge Stephen Williams said State’s requests to Clinton and the FBI for copies of Clinton’s emails were not necessarily enough to fulfill State’s obligation to pursue any missing messages.

“Even though those efforts bore some fruit, the Department has not explained why shaking the tree harder — e.g., by following the statutory mandate to seek action by the Attorney General — might not bear more still. It is therefore abundantly clear that, in terms of assuring government recovery of emails, appellants have not ‘been given everything [they] asked for,'” Williams wrote in the court’s opinion, joined by Judges Brett Kavanaugh and Robert Wilkins. “Absent a showing that the requested enforcement action could not shake loose a few more emails, the case is not moot.”

Clinton turned over about 54,000 pages of messages at State’s request in December 2014. She also instructed her aides to erase a similar quantity of emails her lawyers determined were entirely personal. In August 2015, her attorneys gave thumb drives containing copies of the work-related messages to the Justice Department.

Clinton attorney David Kendall did not immediately respond to a request for comment Tuesday. Clinton and her attorneys previously have said she has no more messages to turn over, whether suits are filed or not.

A spokesman for the Justice Department, which is representing State and the National Archives in the litigation, also declined to comment on the ruling.

The outcome of the appeals court case may have been influenced by the timing of the arguments, which took place in early November, just after FBI Director James Comey revealed in a letter to Congress that his agency had come across more Clinton emails. They were found on a laptop belonging to Anthony Weiner, the estranged husband of longtime Clinton aide Huma Abedin.

Comey’s disclosure of the discovery roiled the final days of the presidential election, even though he announced two days before the vote that the new evidence had not changed the FBI’s conclusions that no prosecution of Clinton was warranted. Many Clinton aides and allies blame Comey’s messages to Congress about the developments for tilting the election to the victor, GOP nominee Donald Trump.

The discovery of the new emails on Weiner’s laptop was in the news as the case was argued and may have dramatized the possibility for the judges that additional Clinton emails exist in places that were not searched by Clinton, her aides, or, at least initially, by the FBI.

Williams does not mention the belatedly discovered emails in the opinion issued Tuesday but seems convinced that turning up more of the messages is a live possibility. He also said the record did not show what State had done to recover emails Clinton exchanged on a separate BlackBerry-based account during the early weeks of her tenure.

“While the case might well … be moot if a referral were pointless (e.g., because no imaginable enforcement action by the Attorney General could lead to recovery of the missing emails), the record here provides no factual support for finding mootness on that basis,” Williams wrote.

The appeals court ruling stops short of ordering the district court to force State to make the Federal Records Act referral to the Justice Department, leaving the possibility the cases could be dismissed on other grounds before such a directive is issued. The D.C. Circuit judges also indicated they were not taking a position on whether the attorney general would be required to sue if presented with a referral on the issue.

Williams was appointed by President Ronald Reagan, Kavanaugh by President George W. Bush and Wilkins by President Barack Obama. The judge who issued the initial decision tossing out the cases, James Boasberg, is also an Obama appointee.