WASHINGTON — The Justice Department has urged a special master to broadly reject assertions by former President Donald J. Trump that he owns a range of documents the F.B.I. seized from his Florida residence and that he can invoke executive privilege to bar criminal investigators from looking at some of them.
But lawyers for Mr. Trump have put forward the opposite case, laying out a sweeping vision of his power to declare documents as his personal property and to keep files from his presidency secret from the Biden-era executive branch.
The opposing views were on display in rival briefs partly unsealed on Monday. The two sides had recently submitted the briefs to Judge Raymond J. Dearie, the special master who is overseeing a process of resolving disputes about the status of some 13,000 documents and photographs seized in August.
The unsealing of the briefs was the latest turn in Mr. Trump’s efforts to keep the Justice Department from using the trove of documents in its investigation into whether he illegally kept national security records at his Mar-a-Lago compound and obstructed the government’s repeated attempts to retrieve them.
Judge Dearie now must write a report recommending whether each of the files that Mr. Trump took with him to Mar-a-Lago is government or personal property, and whether any is protected by attorney-client or executive privilege. The judge who appointed him as special master, Aileen M. Cannon of the Southern District of Florida, will make the final ruling about the status of the documents.
One major issue both judges will confront is the extent of Mr. Trump’s power to deem documents as his personal property. In 2012, a Federal District Court judge ruled that it was up to the president, before he left office, to sort records in the White House as presidential or personal records.
Mr. Trump has invoked the ruling in broad ways, including claiming as his personal property documents submitted to him when he was president discussing various applications for clemency. The Justice Department considers those presidential records, saying they belong to the public and must be deposited with the National Archives.
In its newly unsealed brief, the Justice Department argued that Mr. Trump would have had to designate them as personal property before he left office. It also argued that in any case, he could not deem obviously presidential records as his own property “simply by saying so.”
Such a reading of the Presidential Records Act, the department said, “would nullify the statute’s entire purpose by allowing a president to designate all of his official records as ‘personal records’ and then to remove them upon departure from the White House.”
But Mr. Trump’s brief argued that a president’s decision was final, and that there did not need to be any record of that.
“President Trump need not put forth documentary evidence of his designation decisions, because his conduct unequivocally confirmed that he was treating the materials in question as personal records, rather than presidential records,” his lawyers wrote.
Another major issue is whether Mr. Trump can invoke executive privilege to block the executive branch itself from examining executive branch records for a criminal investigation.
The Justice Department asserted that Mr. Trump could not assert executive privilege in this situation.
“Executive privilege exists ‘for the benefit of the republic,’ not any president as an individual,” prosecutors wrote in their brief, “and plaintiff cannot successfully invoke the privilege to prevent a review of executive branch documents by ‘the very executive branch in whose name the privilege is invoked.’”
But Mr. Trump’s lawyers rejected the idea that executive privilege could never be invoked against the executive branch itself. They said that to hold otherwise would undermine the purpose of the privilege, which is to preserve the ability of a president and his aides to have candid deliberations about presidential decisions.
“Although executive privilege is an important tool in preserving the independence of each branch of government pursuant to the doctrine of separation of powers, it is not limited to that purpose as the government contends,” Mr. Trump’s lawyers contended in their brief.
Most of the arguments over specific documents have been kept from public view because many of those documents have been sealed or redacted, but some glimpses have come to light.
A Justice Department letter filed to Judge Dearie on Saturday said that one of the files compiled several documents, including two marked as classified — one confidential and one secret — and three messages Mr. Trump received after he was no longer president. The messages came from a book author, a religious leader and a pollster, the letter said.
While the letter offered no further details, the finding may be notable because it means that Mr. Trump or someone in his orbit was doing something with some of the documents marked as classified at Mar-a-Lago after Mr. Trump left office. The letter discussed the package because one of its pages was deemed potentially subject to attorney-client privilege, so it was not clear whether there were others such packages that did not raise attorney-client issues.
One open question is what, if anything, Mr. Trump was doing with the government files he took to Mar-a-Lago.
It is possible that the special master review process will get shut down before Judge Dearie completes his report and recommendations, which are due next month, or before Judge Cannon issues any final ruling. The Court of Appeals for the 11th Circuit, in Atlanta, is simultaneously weighing a Justice Department request that it rescind Judge Cannon’s decision to impose a special master.
Judge Cannon, an appointee of Mr. Trump, surprised legal observers by intervening and granting the former president’s request for a master to vet the materials, and by accepting the possibility that executive privilege could be used by an ex-president to block executive branch criminal investigators from seeing executive branch files.
The 11th Circuit already rolled back part of Judge Cannon’s order, which had blocked criminal investigators from the 103 documents marked as classified. Mr. Trump partly appealed it, arguing that the court lacked jurisdiction to remove such files from the special master review process, but the Supreme Court declined to side with him.
In a 65-page brief filed last week, Christopher Kise and James Trusty, lawyers for Mr. Trump, urged the appellate court to let the special master process continue playing out, arguing in part that Judge Cannon’s blocking of the criminal investigators from using the documents until the review is done will bolster “public trust and the perception of fairness.”
“Given the significance of this investigation, it must be conducted in a manner that gives the public confidence in its outcome,” they wrote.