President Joe Biden’s lawyers discovered “a small number” of classified documents in his former office at a Washington think tank last fall, the White House said on Monday, prompting the justice department to scrutinise the situation.

The inquiry, according to two people familiar with the matter, is a type aimed at helping attorney general Merrick B. Garland decide whether to appoint a special counsel, like the one investigating former President Donald J. Trump’s hoarding of sensitive documents and failure to return all of them.

The documents found in Biden’s former office, which date to his time as vice president, were found by his personal lawyers on November2, when they were packing files at the Penn Biden Center for Diplomacy and Global Engagement.

The White House said in a statement that the White House Counsel’s Office notified the National Archives and Records Administration on the same day the documents were found “in a locked closet” and that the agency retrieved them the next morning.

Biden had periodically used an office at the centre from mid-2017 until the start of the 2020 presidential campaign, and the lawyers were packing it up in preparations to vacate the space. The discovery was not in response to any prior request from the archives.