The FBI has located additional documents with classified markings in a search of US President Joe Biden’s home in Delaware, and also took possession of some of his handwritten notes, his lawyer has said.

Bob Bauer said the Justice Department (DOJ) conducted the search at Mr Biden’s Wilmington residence on Friday. The president voluntarily allowed the FBI into his home, there was no search warrant, and the search lasted about 13 hours.

The Justice Department “took possession of materials it deemed within the scope of its inquiry, including six items consisting of documents with classification markings and surrounding materials, some of which were from the president’s service in the Senate and some of which were from his tenure as vice-president,” Mr Bauer said in a statement.

Joe Biden's home
The FBI spent 13 hours searching Joe Biden’s home in Wilmington, Delaware (Carolyn Kaster/AP)

The prosecutors also “took for further review personally handwritten notes from the vice-presidential years”, he said.

The level of classification, and whether they remained classified, was not immediately clear as the Justice Department reviews the records.

Generally, classified documents are declassified after a maximum of 25 years. But some records are of such value they remain classified for far longer, though specific exceptions must be granted. Mr Biden served in the Senate from 1973 to 2009.

The search followed more than a week after Mr Biden’s lawyers found six other classified documents in his home library from his time as vice-president, and nearly three months after lawyers found a small number of classified records at his former offices at the Penn Biden Centre in Washington.

Though Mr Biden has maintained “there’s no there there” on the document discoveries, they have become a political liability as he prepares to launch a re-election bid, and they undercut his efforts to portray an image of propriety to the American public after the tumultuous presidency of his predecessor Donald Trump.

Trump Lawsuits
Former president Donald Trump is under investigation over the suspected retention of documents (Andrew Harnik/AP/PA)

The president and First Lady Jill Biden were not at the home when it was searched on Friday.

Mr Bauer said the FBI had asked the White House not to comment on the search before it was conducted. He said the FBI “had full access to the president’s home, including personally handwritten notes, files, papers, binders, memorabilia, to-do lists, schedules, and reminders going back decades”.

Assistant US Attorney Joseph Fitzpatrick said the FBI had executed “a planned, consensual search” of the president’s residence in Wilmington.

Speaking to reporters during a trip to California on Thursday, Mr Biden said he was “fully co-operating and looking forward to getting this resolved quickly”.

He added: “We found a handful of documents were filed in the wrong place. We immediately turned them over to the Archives and the Justice Department.”

It remains to be seen whether additional searches by federal officials of other locations might be conducted. Mr Biden’s personal attorneys previously conducted a search of his residence at Rehoboth Beach in Delaware and said they did not find any official documents or classified records.

Joe Biden
The White House said Mr Biden has co-operated at every stage of the investigation (Susan Walsh/AP)

The Biden investigation has complicated the Justice Department’s probe into Mr Trump’s retention of classified documents and official records after he left office.

The Justice Department says Mr Trump took hundreds of records marked classified with him upon leaving the White House in early 2021 and resisted months of requests to return them to the government, and that it had to obtain a search warrant to retrieve them.

But the Biden document discoveries and the investigation into Mr Trump are significantly different. Mr Biden has made a point of co-operating with the Justice Department probe at every turn, though questions about his transparency with the public remain.

For a crime to have been committed, a person would have to “knowingly remove” the documents without authority and intend to keep them at an “unauthorised location”. Mr Biden has said he was “surprised” that classified documents were uncovered at the Penn Biden Centre.

White House lawyer Richard Sauber said on Saturday: “Since the beginning, the president has been committed to handling this responsibly because he takes this seriously.

“The president’s lawyers and White House counsel’s office will continue to co-operate with DOJ and the special counsel to help ensure this process is conducted swiftly and efficiently.”