Fourteen boxes out of fifteen recovered from the property of former U.S. President Donald Trump in Florida earlier this year contained documents classified as top secret, according to an affidavit from the FBI released on Friday.

The 32-page affidavit, in its redacted form, provides a detailed description of the government records stored at Trump's property, long after he left the White House, revealing the severity of the government's concerns that the documents were there unlawfully.

One FBI agent wrote on the first page of the affidavit, in a request for permission from the judge: "The government is conducting a criminal investigation into the improper removal and storage of classified information in unauthorized locations, as well as the illegal concealment or deletion of government records."

The affidavit does not provide new details about the 11 sets of classified records recovered during the search on August 8 at Mar-a-Lago, but instead relates to a separate group of 15 boxes retrieved by the National Archives and Records Administration from the home in January.

The FBI submitted the affidavit, or sworn statement, to the judge in order to obtain a search warrant for Trump's property.

In a separate document disclosed on Friday, Justice Department officials explained that it was necessary to redact some information "to protect the safety and privacy of a large number of civilian witnesses, as well as law enforcement personnel, and to protect the integrity of the ongoing investigation."