WASHINGTON, Sept 15 (Reuters) – A U.S. judge on Thursday refused to allow the Justice Department to immediately resume a review of classified files seized by the FBI from Donald Trump’s Florida estate in an ongoing criminal investigation into the former president. Federal Judge Aileen Cannon also appointed Senior District Judge Raymond Dearie as a third party to review records seized by the FBI for material that could be privileged and withheld by federal investigators. The Justice Department has promised to take the case to an appeals court if Cannon rules against their request. They also tried to block the independent arbitrator, Dearie, from reviewing about 100 classified documents included among the 11,000 records gathered in the Aug. 8 court-authorized search. Sign up now for FREE unlimited access to Reuters.comSign up “The court does not see fit to accept the government’s conclusions on these important and contested issues without further review by a neutral third party in an expeditious and orderly manner,” Cannon wrote Thursday. A Justice Department spokesman and Trump’s lawyers did not immediately return requests for comment. Cannon’s decision further complicates the Justice Department’s investigation. The master’s special review could exclude documents from prosecutors as they weigh the possibility of criminal charges. Cannon on Thursday said she would instruct Dearie to prioritize reviewing classified records first. It also asked him to complete the inspection of all seized materials by November 30. The Justice Department is investigating Trump for keeping government records — some classified as top secret, including “top secret” — at his Mar-a-Lago estate in Palm Beach after he leaves office in January 2021. The department is also looking into possible obstruction of justice after finding evidence that records may have been removed or hidden by the FBI when it sent agents to Mar-a-Lago in June to try to retrieve all classified documents through a grand jury subpoena. . The probe into the documents is one of several federal and state probes facing Trump as he considers another run for the presidency in 2024. The Justice Department on Sept. 8 asked the judge to partially lift her previous restriction barring its investigators from reviewing all the documents seized last month at Mar-a-Lago, so that they could at least continue to examine those marked as graded. They also asked the judge to exempt those classified records from the master’s scope of special review, vowing to appeal to the Atlanta-based 11th U.S. Circuit Court of Appeals if he did not. Trump’s lawyers opposed both requests, telling the judge in a Monday filing that they dispute the administration’s contention that all records are classified and that a special master is needed to keep prosecutors in check. Trump’s lawyers in Monday’s filing disputed the department’s claim that the roughly 100 documents at issue are actually classified and reminded Cannon that a president generally has broad powers to declassify records. They stopped short of suggesting Trump had declassified the documents, a claim he has made on social media but not in court filings. About two weeks after the investigation, Trump’s lawyers sought the appointment of a special master to review the seized records for material that could be covered by attorney-client privilege or executive privilege — a legal doctrine that can protect some presidential records since the revelation. In ruling on Sept. 5 in favor of Trump’s request, Cannon rejected the Justice Department’s arguments that the records belong to the government and that because Trump is no longer president he cannot claim executive privilege. Cannon was appointed to the bench by Trump in 2020. Sign up now for FREE unlimited access to Reuters.comSign up Report by Sarah N. Lynch and Jacqueline Thomsen. Editing by Chris Reese and Christopher Cushing Our Standards: The Thomson Reuters Trust Principles.