This image contained in a court filing by the Department of Justice on Aug. 30, 2022, and partially redacted by the source, shows a photo of documents seized during the Aug. 8, 2022, FBI search of former President Donald Trump's Mar-a-Lago estate. (AP)

Court documents revealed on Friday that the classified papers former US President Donald Trump had kept in his Mar-a-Lago residence in Florida were found by investigators in the bedroom, the bathroom and shower, a storage room, a ballroom, and his office.

Trump is reportedly facing 37 felony charges related to the mishandling of classified documents, including 31 counts of willful retention of national defense information.

If convicted, the former President may also face prison time, with some of the charges carrying sentences of up to 20 years in prison, according to the indictment unsealed by the federal court.

"In April 2021, some of Trump's boxes were moved from the business center to a bathroom and shower in The Mar-a-Lago Club's Lake Room," the indictment stated, noting that boxes that were located in the Lake room were moved to the Storage room which had more than 80 boxes when investigators searched the premises.

It further states that Trump had 17 documents labeled top secret, 54 documents labeled secret, and 3 documents labeled confidential at his Mar-a-Lago residence.

Some of the documents included information about defense and weapons capabilities of the US and foreign countries, US nuclear programs, potential vulnerabilities of the US and its allies to military attack, and plans for possible retaliation in response to a foreign attack, the indictment states.

It further states that unauthorized disclosure of such information may put at risk US national security, foreign relations, and US intelligence gathering methods.

Special counsel Jack Smith, named by US Attorney General Merrick Garland, has been looking into a stockpile of classified documents that Trump had stored at his Mar-a-Lago residence in Florida after leaving the White House.

The FBI transported some 11,000 papers after serving a search warrant on Mar-a-Lago in August, and obstruction-of-justice charges could be a result of his resisting efforts to recover the cache.

Trump eventually turned over 15 boxes containing almost 200 classified documents to the National Archives in January 2022 but was subpoenaed for any outstanding records in his possession.

Trump has repeatedly denied wrongdoing in the case. But he has openly acknowledged taking and storing the documents, undermining his lawyers' suggestion that he took the documents unintentionally.

While the former President has repeatedly denied wrongdoing, he has openly acknowledged taking and storing the documents, undermining his lawyers' suggestion that he took the documents unintentionally.

On Tuesday, Trump is expected to appear at a federal courthouse in Miami for proceedings.

He has previously criticized the Justice Department for not looking into President Joe Biden’s alleged mishandling of sensitive information.