The warrant indicates that FBI agents were looking into potential violations of the Espionage Act, which makes it illegal to keep or transmit potentially dangerous national security information.

The removal of classified documents or materials is prohibited by law - a crime for which Mr Trump increased the penalties while in office. It is now punishable by up to five years in prison.

The warrant notes that the locations searched at Mar-a-Lago include an area called the "45 office" and storage rooms, but not private guest suites being used by Mr Trump and his staff. It was approved by a judge on 5 August, three days before it was carried out on Monday, 8 August.

In a statement on his Truth Social platform, Mr Trump said the items recovered were "all declassified" and securely stored.

He said he would have been willing to hand the items over before the search warrant was carried out.

"They could have had it anytime they wanted - and that includes long ago," he said. "All they had to do was ask."

A spokesman for Mr Trump, Taylor Budowich, told the BBC's US partner, CBS News, that the administration of Joe Biden "is in obvious damage control after their botched raid".

Mr Budowich added that the search was "not just unprecedented, but unnecessary". He also accused the administration of "leaking lies and innuendos to try explain away the weaponization of government against their dominant political opponent".