The FBI found no classified-marked documents during a planned search of Joe Biden's vacation home in Rehoboth Beach, Delaware, on Wednesday, a person familiar with the matter said, as federal investigators continued to look into the potential mishandling of classified information.
The search was consensual and performed with the cooperation of Biden and his legal team, who previously searched the property and found no marked documents.
The FBI took some materials and handwritten notes from Biden's time as vice-president.
In a statement earlier on Wednesday announcing the search, Biden's personal lawyer, Bob Bauer, said: "Today, with the president's full support and cooperation, the Department of Justice is conducting a planned search of his home in Rehoboth, Delaware.
"Under DoJ's standard procedures, in the interests of operational security and integrity, it sought to do this work without advance public notice, and we agreed to cooperate."
Biden has voluntarily allowed the justice department to search his properties in recent weeks, as investigators seek to determine how classified-marked documents from Biden's time as vice-president and senator ended up in private office space and inside his residence.
The department opened an investigation after the 2 November discovery by Biden's personal lawyers of classified-marked documents in his office at the University of Pennsylvania Biden Center in Washington, a thinktank where he was an honorary professor until 2019.
Biden's lawyers found additional documents at his residence in Wilmington, Delaware. The FBI searched the Penn Biden Center in mid-November, as well as Biden's Wilmington home on 20 January, when agents took possession of more documents and some handwritten notes.
On Wednesday, a spokesperson for the justice department declined to comment on the FBI action.
On conclusion of the search, Bauer said the "planned search of the president's Rehoboth residences, conducted in coordination and cooperation with the president's attorneys, has concluded. The search was conducted from 8.30am to noon. No documents with classified markings were found.
"Consistent with the process in Wilmington, the DoJ took for further review some materials and handwritten notes that appear to relate to [Biden's] time as vice-president."
The president's cooperative stance as the investigation has progressed - and as the attorney general, Merrick Garland, appointed a Trump justice department official, Robert Hur, as special counsel - stands in stark contrast to the parallel investigation into Donald Trump.
Trump remains the subject of an investigation overseen by another special counsel, Jack Smith, the former head of the justice department public integrity section, who is examining possible unauthorised retention of national security materials and obstruction of justice.
The department has indicated a particular focus on obstruction, noting that Trump and his lawyers did not fully comply with a grand jury subpoena last May, seeking the return of all classified-marked documents that led to an FBI search of Mar-a-Lago in August.
The FBI seized around 100 documents bearing classification markings, which the justice department has contended should have been returned to the government under the subpoena, which sought all such marked papers regardless of whether they had been declassified, as Trump has suggested they were.
For months, Trump also resisted conducting a search for any classified documents the department suspected were still in his possession, even after the FBI seized classified materials. That second search turned up at least two more classified documents.
By contrast, the classified documents found last year at the Biden office in Washington were returned to the National Archives as soon as they were discovered, as the office was being closed down.
Trump's vice-president, Mike Pence, was recently discovered to have classified-marked documents at his home in Indiana. Pence's lawyer immediately alerted authorities and returned the materials to the government.