The U.S. Department of Justice (DOJ) conducted a "planned search" of President Joe Biden's home in Delaware, on Wednesday, though no classified documents were found there.

The DOJ did not find documents with classified markings during the three-and-a-half hour search of Biden's beach house in Rehoboth, Delaware, but did take some materials for further review, Biden's attorney said.

The morning search, conducted by the FBI, which is part of the Justice Department, appeared to represent an expansion of the probe into Biden's handling of classified documents.

Materials were previously found at his home in Wilmington, Delaware, and at a Washington office he used during the time between his service as vice president under Barack Obama and his presidential election.

The DOJ conducted a search of Biden's home in Wilmington, Delaware, on January 20.

Political headache

The issue has created a political headache for Biden, who is expected to announce a re-election campaign in the coming weeks or months. It has stripped him and fellow Democrats of a political weapon to use against former President Donald Trump, who also had classified documents found at his home.

Classified documents have also been found in the home of former U.S. Vice President Mike Pence of the Trump administration, giving some political cover to Biden.

Biden has vowed to cooperate with the searches and Pence had said he takes responsibility for the found documents. Trump resisted efforts to return materials in his possession, prompting a FBI search of his Florida home and resort last year.

U.S. Attorney General Merrick Garland has appointed two separate special counsels to review Trump and Biden's handling of such documents.

Meanwhile, the National Archives has reportedly asked all former U.S. presidents and vice presidents to search their personal records for classified documents or other presidential material that should have been turned over when they left office.

It is unlawful to knowingly or willfully remove or retain classified material, although no current or former president or vice president has been charged with wrongdoing.

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(With input from Xinhua, Reuters)