FBI agents found dozens of empty folders marked as classified during a search of Donald Trump's Florida home last month, a court filing shows, BBC News reported.

The document, made public by a Florida court, provides an inventory of the contents of 33 boxes recovered from the former president's Mar-a-Lago estate.

It also shows top secret files were recovered from his personal office.

Trump, who is being investigated over his handling of classified records, denies wrongdoing.

Previous court filings have confirmed the ex-president held classified records in storage areas at Mar-a-Lago, but the document unsealed on Friday showed dozens of files were found in Trump's office.

Among the files allegedly recovered from that room during the unprecedented 8 August search were: 3 documents marked “confidential,” 17 documents marked “secret,” 7 documents marked “top secret,”  43 empty folders with classified banners, and 28 empty folders labeled "Return to staff secretary/military aide."

More than 11,000 government documents in total were retrieved by the FBI from the Palm Beach estate, say investigators.

US presidents must transfer all of their documents and emails to the National Archives. The justice department is looking into whether Trump improperly handled records by taking them from the White House to his Mar-a-Lago estate after he left office in January 2021.

Prosecutors allege Trump and his lawyers failed to provide relevant documents voluntarily, and "likely concealed or removed" records as part of an effort to obstruct the investigation.

Trump has rebuked these claims, arguing he had already declassified the documents that were in his possession. He has also argued that the files were kept securely in a storage room at Mar-a-Lago.