US President Joe Biden’s aides have found a fresh batch of classified government records at a second location, in a growing political embarrassment for the White House.
The first cache was found at a private office in Washington DC that Mr Biden used after his vice-presidency.
The matter is under review by the US Department of Justice.
Former President Donald Trump is facing a criminal investigation for allegedly mishandling classified files.
The original batch of about 10 documents was discovered in November at the Penn Biden Center, a think tank near the White House, but only came to light this week.
Those papers reportedly include US intelligence memos and briefing materials related to Ukraine, Iran and the United Kingdom.
They relate to his time as vice-president under President Barack Obama but it is unclear why they turned up in a private office he started using after that.
Access to classified documents is limited by law to people with special authorisation and there are rules about how they are kept and stored.
All White House records, including classified ones, are required to be turned over to the US National Archives after an administration’s time in office.
BBC