Classified documents have been found at former US Vice-President Mike Pence's home in the latest secret paper discovery.

The documents, discovered by a lawyer last week for Mr Pence at his Indiana home, have been handed over to the FBI.

Special counsels are already looking at the handling of classified documents by President Joe Biden and ex-President Donald Trump.

Mr Trump faces a criminal investigation for allegedly mishandling files.

Representatives for Mr Pence sent a letter to the National Archives alerting them to the documents. The FBI came to the former vice-president's home to collect them, they added in a separate letter.

A "small number of documents bearing classified markings" were "inadvertently boxed and transported" to Mr Pence's home at the end of Donald Trump's presidency, his lawyer wrote in a letter shared with US media.

Mr Pence sought counsel who specialise in handling classified documents to review documents at his home "after it became public that documents with classified markings were found in President Joe Biden's Wilmington residence", the letter read.

Six more classified documents were found during a 13-hour search of President Biden's home in Delaware on Friday.

The president offered access "to his home to allow DoJ [the Department of Justice] to conduct a search of the entire premises for potential vice-presidential records and potential classified material", Mr Bauer said in a statement on Saturday.

Earlier this month, Mr Biden's lawyers said a first batch of classified documents had been found on 2 November at the Penn Biden Center, a think tank that the president founded in Washington DC.

A second batch of records was found on 20 December in the garage at his Wilmington home, while another document was found in a storage space at the house on 12 January, his lawyers said.