WASHINGTON: US Attorney General Merrick Garland announced Thursday the appointment of a special counsel to investigate President Joe Biden's classified documents matter.

The appointment of Robert Hur came after the discovery of two batches of classified documents from Biden while he was vice president.

Garland said he notified designated members of each house of Congress of the appointment, Anadolu Agency reported.

He said he signed an order appointing Hur to the matter, which he said authorises him to investigate if any person or entity violated the law.

The White House said earlier that more classified documents were found at Biden's home in Wilmington, Delaware -- most in a storage space in the garage.

Special Counsel to Biden, Richard Sauber, said Biden's lawyers searched his Wilmington and Rehoboth Beach, Delaware, residences after classified documents were found at the Penn Biden Center in November.

Biden's attorneys found the first batch of about 10 documents at the Penn Biden Center for Diplomacy and Global Engagement in Washington, D.C. in a locked closet as they were preparing to vacate the office space and handed them to the National Archives and Records Administration.

They included documents containing US intelligence memos and briefing materials dated between 2013 and 2016 related to Ukraine, Iran and the UK, a source told CNN.

It was also reported that Biden said he was surprised to learn classified documents from his time as vice president were found at the office of his think tank, adding that his team "immediately" handed them to the National Archives.

The White House said after the appointment of Hur that it is confident the investigation will show that Biden accidentally misplaced the documents.

"We are confident that a thorough review will show that these documents were inadvertently misplaced, and the President and his lawyers acted promptly upon discovery of this mistake," it quoted Sauber said in a statement.

White House has "cooperated closely with the Justice Department throughout its review, and we will continue that cooperation with the Special Counsel," he added.

-- BERNAMA