A batch of records from President Biden's time as Vice President, including a "small number of documents with classified markings," were discovered at the Penn Biden Center by the president's personal attorneys on Nov. 2, according to Richard Sauber, special counsel to the White House.
The attorneys found the documents in a locked closet while preparing to vacate office space at the center, which the president used from mid-2017 until he began the 2020 campaign.
The National Archives were notified of the finding and took possession of the documents on Nov. 3, 2022, Sauber said.
"The documents were not the subject of any previous request or inquiry by the Archives," Sauber said in a statement. "Since that discovery, the President's personal attorneys have cooperated with he Archives and the Department of Justice in process to ensure that any Obama-Biden Administration records are appropriately in the possession of the Archives."
Attorney General Merrick Garland appointed U.S. Attorney for the Northern District of Illinois John Lausch to review the matter, according to CBS News, which first reported on the documents' discovery on Monday.
Biden slammed former President Trump last year after FBI agents seized approximately 300 classified documents from his Mar-a-Lago home in Florida.
"How that could possibly happen? How anyone could be that irresponsible? And I thought what data was in there that would maybe compromise sources and methods?" the president told 60 Minutes. "And it just – totally irresponsible."
Under the Presidential Records Act, all documents from a president's administration and staff must be turned over to the National Archives.
Jack Smith, a former assistant U.S. attorney and chief to the DOJ's public integrity section, was appointed as special counsel to investigate the records seized from Mar-a-Lago.
Trump, who launched his 2024 bid in November, has said he'll refuse to cooperate with the special counsel's investigation.
"When is the FBI going to raid the many homes of Joe Biden, perhaps even the White House?" Trump wrote on Truth Social on Monday. "These documents were definitely not declassified."
Rep. James Comer, R-Ky., the Chairman of the House Oversight Committee, said that he will send a letter to the National Archives and White House counsel seeking information about the documents that were seized from the Penn Biden Center.
"Under the Biden Administration, the Department of Justice and National Archives have made compliance with the Presidential Records Act a top priority," Comer said in a statement. "We expect the same treatment for President Biden, who has apparently inappropriately maintained classified documents in an insecure setting for several years."
The Penn Biden Center for Diplomacy and Global Engagement is affiliated with the University of Pennsylvania, but opened its doors in Washington, D.C., in February 2018.
The think tank's stated mission is to engage "Penn’s students and partners with its faculty and global centers to convene world leaders, develop and advance smart policy, and strengthen the national debate for continued American global leadership in the 21st century."
The Department of Justice and National Archives did not immediately respond to a request for comment on Monday.
Fox News' Kelly Phares contributed to this report.