"Thank you notes, Christmas ornaments, magazines, and clothing" were found scattered among the United States' "most highly guarded secrets" in boxes at Donald Trump's Mar-a-Lago resort, according to new court documents.

New photos have shown the extent of the "clutter" faced by FBI agents, who were forced to search the building in "filter teams" to avoid accidentally viewing top-secret material.

The August 2022 search formed part of an ongoing criminal investigation into the former president's potential mishandling of government secrets.

Mr Trump, along with his aide Walt Nauta and Mar-a-Lago property manager Carlos de Oliveira, have all been charged over the case.

All three have pleaded not guilty.

The newly revealed photos were included as part of a filing in the federal court case, a response by special counsel Jack Smith in the wake of Mr Trump's efforts to suppress all evidence.

Mr Trump has accused agents of moving the order of documents found inside each box.

The latest filing called the accusation "merit-less".

"Newspapers, thank you notes, Christmas ornaments, magazines, clothing, and photographs of himself and others.

"At the end of his presidency, he took his cluttered collection of keepsakes to Mar-a-Lago, his personal residence and social club.

"[Here] the boxes travelled from one readily accessible location to another — a public ballroom, an office space, a bathroom, and a basement storage room.

"After they landed in stacks in the storage room, several boxes fell and splayed their contents on the floor, and boxes were moved to Trump's residence on more than one occasion so he could review and pick through them."

'Nigh impossible' to keep documents in exact order

Cameras were rolling as FBI agents raided Mar-a-Lago in August 2022 — with Mr Trump declaring the building had been "under siege" and "occupied".

But beyond the armed police and pro-Trump supporters gathered outside, investigators faced a particular challenge.

The "cluttered" state of the boxes and the volume of documents involved were unprecedented.

Each room had to first be searched by the Filter Team — dubbed the "Privilege Review Team" in the search warrant.

This team would search for "any potentially attorney-client privileged material" so the "Case Team", made up of agents investigating the case, would not be exposed.

"If the Filter Team came across any potentially privileged materials, the entire box … was to be segregated away from access by any member of the Case Team," the prosecution said.

"[It would be] set aside for later, more thorough inspection by filter agents in the Washington Field Office."

If a box was cleared by the Filter Team, it would go back to the Case Team, who would then search it for classified material.

"Despite that, the agents did the best they could under the circumstances."

During the search, still more agents and an Evidence Response Team set up a workspace to sift through boxes cleared by the Filter Team.

Classified documents were "removed" and "segregated", and "replaced with a placeholder sheet" showing where they had been removed.

"They used pre-printed classified cover sheets for the initial placeholder sheets until they ran out of them, having not anticipated finding so many classified documents," the prosecution said.