Biden met with Special Counsel Robert Hur over two days at the White House.

A separate investigation into secret documents found at Donald Trump’s home led to the appointment of Mr Hur.

Biden has not been charged with any crimes. Investigators often interview presidents.

In a statement, Mr Biden’s spokesman Ian Sams said the interview was conducted over Sunday and Monday.

The investigation was personally conducted by Mr Hur, who was chosen by US Attorney General Merrick Garland to lead it. Monday’s interview had “concluded,” he said.

As we have said from the beginning, the President and the White House are cooperating with this investigation, and we have provided relevant updates publicly as needed, keeping the integrity of the investigation intact as much as possible,” Mr Sams told reporters.

At this time, we will refer other questions to the Justice Department.

Mr Biden’s aides discovered the documents in an office he used after leaving the vice-presidency and before launching his presidential bid. In Washington, DC, the Penn Biden Center, a think tank founded by the president, found the first batch of classified documents on 2 November.

His lawyers said that another batch of records were found in the garage of his Wilmington home on 20 December, and another document was found in a storage area on 12 January.

The president said his team immediately turned over the documents to the National Archives and the Justice Department after finding them. Mr Biden’s reasons for keeping them are unclear.