The possible classified material was discovered among more than a dozen boxes of presidential records from former US President Donald Trump's Mar-a-Lago resort in Florida in January, according to a report.
The discovery prompted the US National Archives and Records Administration to alert the Department of Justice (DOJ), The New York Times reported on Thursday.
An unnamed source told the newspaper that the possible classified material was discovered last month when 15 boxes of presidential records were recovered from the Florida resort.
The Department of Justice is reportedly looking int to the matter.
The Washington Post also published a report earlier this week claiming that numerous White House record boxes had been recovered by the National Archives in January from Mar-a-Lago. Among the materials were communication, gifts, and letters from world leaders.
Storing the presidential documents at Mar-a-Lago is a possible violation of the Presidential Records Act, which has been common in other recent presidential administrations as well.
However, transferring the documents to the Florida report was "out of the ordinary."
The National Archives had reportedly also requested the DOJ to investigate Trump's handling of White House records, though it remains unclear if the department will launch an inquiry.
The National Archives had alleged that it received documents from the Trump administration that had been torn apart and taped back together.
Trump would reportedly regularly rip up documents during his time in office. Politico spoke with former Trump administration staffer Solomon Lartey in 2018, who said his first five months in the Trump White House were spent taping documents back together.
“You found pieces and taped them back together and then you gave it back to the supervisor," Lartey told the outlet.
“I had a letter from Schumer — he tore it up,” said Lartey, referring to Senate Majority Leader Charles Schumer (D-N.Y.). “It was the craziest thing ever. He ripped papers into tiny pieces.”