WASHINGTON (AP) — The FBI searched President Joe Biden's former office at the Penn Biden Center in Washington in November, according to a person familiar with the matter, weeks after his personal lawyers first found classified records there from his time as vice president.

The discovery of the documents at the office blocks away from the U.S. Capitol led to a search of Biden's homes, including his residence in Wilmington, Delaware, where lawyers and federal agents found additional classified documents in December and January. It was not immediately clear whether the FBI search of Biden's office uncovered additional classified documents beyond those found on Nov. 2 by Biden's attorneys. The person spoke on the condition of anonymity to discuss a law enforcement action.

News of the FBI search is the latest uncomfortable development for Biden, who pledged to turn the page on the norm- and rule-breaking tenure of his predecessor, Donald Trump.

Attorney General Merrick Garland has appointed a special counsel to lead an investigation into how the documents ended up at Biden's home and former office and whether any laws were broken. Trump is facing a far more perilous investigation by a separate special counsel after repeatedly refusing federal efforts to recover classified and official records at his Florida estate.

In the wake of the Biden disclosures, former Vice President Mike Pence said he found classified documents at his Indiana residence and the National Archives has requested that former presidents and vice presidents dating back to the Reagan administration search for any potentially classified or government records improperly in their possession.

Word of the November search of the Penn Biden Center was first reported Tuesday by CBS News, whose initial inquiries about the discovery of classified information at the Biden office sparked the first White House acknowledgement of their discovery.

The White House and the president's personal lawyers, who have faced criticism from Republicans and even some Democrats for their delayed and incomplete disclosure of information about the classified document discoveries, did not directly reveal the search or comment on the matter Tuesday. An FBI spokesman declined comment.

In a Jan. 21 statement acknowledging that FBI agents had searched and taken custody of classified records at the president's Wilmington home the day before, Bob Bauer, the president's personal attorney said the search "was consistent with the process described in the Statement we released on January 14 and followed after the personal attorney's discovery of the documents found at the Penn Biden Center."

The White House and Biden's personal attorneys have not revealed whether the FBI has already or will search Biden's home in Rehoboth Beach, Delaware. His lawyers previously searched that residence and said they did not identify any classified documents or government records there.

The University of Pennsylvania, which runs the Biden Center, did not respond to a request for comment.