On Thursday, Biden's legal team acknowledged it had found a batch of classified documents relating to his time as vice president in the Obama administration at his Delaware home, including some in his garage. Aides had previously found another batch of classified documents at his residence, as well as at a Washington think tank he was associated with.

The Justice Department on Thursday announced it was appointing a special prosecutor to oversee the Biden documents inquiry.

The probe is a distraction for the Democratic president, who has criticized his Republican predecessor Donald Trump's handling of classified material, and could cast a shadow over Biden as both he and Trump gear up for a possible 2024 election rematch.

It also provides fodder for House Republicans, who have pledged to focus their new majority on a number of investigations into the Biden administration.

In addition to examining Biden's handling of classified documents, Republicans are preparing to probe Hunter Biden's past business dealings in Ukraine.

In a letter to the White House released on Friday, Representative James Comer, the Republican chairman of the House Oversight Committee, said the address where the documents were found was listed as Hunter Biden's address on his driver's license through 2018.

"The Committee is concerned President Biden stored classified documents at the same location his son resided while engaging in international business deals with adversaries of the United States," the letter read.

White House officials were not immediately available for comment.

Republicans have sought to compare the investigation of Biden's handling of classified documents to the ongoing probe into how Trump handled classified documents after his presidency.

But their cases are not the same, legal experts say.

The White House said Biden's attorneys found a small number of classified documents and turned them over after discovery. Trump resisted doing so until an August FBI search turned up about 100 classified documents, raising questions about whether Trump or his staff obstructed the investigation.

(Reporting by Gram Slattery; Editing by Richard Cowan and Josie Kao)

By Gram Slattery