The revelation, made in court filings, raises possibility of new criminal implications following Mar-a-Lago raid.
The United States Department of Justice (DOJ) has said it has evidence that classified documents were deliberately concealed from federal investigators at former President Donald Trump’s Mar-a-Lago estate and that “efforts were likely taken to obstruct the government’s investigation”.
The revelation, made in a court filing late on Tuesday, is the latest twist in the federal investigation of Trump’s removal of sensitive documents from the White House and follows an extraordinary raid of the former president’s property in August.
In the documents, the Federal Bureau of Investigation (FBI), the investigative arm of the DOJ, said it had been told by Trump representatives in June that a “diligent search” of the Florida estate had turned up all sensitive material investigators suspected was being kept at the property. At the time, the Trump representatives gave the investigators an envelope containing 38 classified documents.
However, the FBI search of the property on August 8 turned up an additional 33 boxes of documents and other items, some of which were marked “top secret” – the highest classification level used by the US intelligence community.
During the June visit, Trump’s lawyers also told investigators that all records that had come from the White House were kept in a single storage room at the property.
The lawyers said “there were no other records stored in any private office space or other location at the premises and that all available boxes were searched”, according to the court filing.
However, FBI investigators said they later “developed evidence that government records were likely concealed and removed from the storage room and that efforts were likely taken to obstruct the government’s investigation”.
The agency also released a photo showing the cover pages of several paperclip-bound classified documents seized from Mar-a-Lago. Some of the documents bear the words “TOP SECRET”.
The image casts doubt on one of several claims made by Trump and his representatives that sensitive documents were inadvertently packed and removed from the White House.
The FBI documents revealing the new details were filed in opposition to a request by Trump’s legal team for a “special master” to review the seized material.
A special master is an independent third party sometimes appointed by a court in sensitive cases to assure evidence is not improperly viewed by investigators.
A judge was set to hear arguments on the matter on Thursday.
The existence of sensitive documents at Mar-a-Lago came to light at the beginning of the year after the National Archive, which supervises whether former presidents follow legally mandated archival requirements, requested several boxes of files that had apparently been removed from the White House.
Trump later returned 15 boxes containing about 184 documents. The National Archives turned the material over to the FBI after some documents were found to contain classified material, including privileged information on intelligence-gathering and clandestine human sources. The incident piqued concerns that more documents were being held at Mar-a-Lago.
A search warrant previously released by the FBI said Trump was being investigated for possibly violating three laws: a law banning the unauthorised removal or destruction of records from a federal office; a law prohibiting the falsification or destruction of records in a federal investigation; and the so-called Espionage Act, which bans “gathering, transmitting or losing” information related to defence with the intent the information could be used to harm US national security or interests.
Breaking any of the laws could result in a fine or jail time, with the combined offences carrying a maximum of 33 years in prison, although no charges have so far been filed in the case.
It remains unclear if investigators also planned to pursue obstruction of justice charges.
Trump, who has stoked speculation he will run again for president in 2024, has seized on the investigation as further proof he is being politically targeted.
His defence for having the documents has shifted, although his lawyers have maintained he had previously declassified them under his broad presidential powers.
A wider reason for why Trump would retain sensitive documents has not emerged.
The former president is currently the subject of several criminal investigations, including a New York probe looking into whether the former president and his company misrepresented their assets to maximise financial benefits.
A district attorney in Georgia is also investigating if Trump committed any crimes when he pressured a state election official in an attempt to change the state’s vote count in the 2020 presidential election.