The FBI’s search of former President Donald J.Trump’s Florida club and residence last month recovered 48 empty folders marked as containing classified information, a newly disclosed court filing shows, raising the question of whether the government had fully recovered the documents or any remain missing.

The filing, a detailed list of items retrieved in the search, was unsealed on Friday as part of the court fight over whether to appoint an independent arbiter to review the materials taken by federal agents when they descended on Trump’s estate, Mar-a-Lago, on August 8.

Along with the empty folders with classified markings, the FBI also recovered 40 more empty folders that said they contained sensitive documents the user should “return to staff secretary/military aide”, the inventory said.

It also said that agents found seven documents marked as“top secret” in Trump’s office and 11 more in a storage room.

The list and an accompanying court filing from the justice department did not say if all the contents of the empty folders had been recovered.

But the filing noted that the inquiry into Trump’s handling of the documents remained “an active criminal investigation”.

The inventory listed seven batches of materials taken by the FBI from Trump’s personal office at Mar-a-Lago that contained government-owned documents and photographs— some marked with classification levels up to “top secret” and some that were not marked as classified.

The list also included batches of government documents that had been in 26 boxes or containers in a storage room at the compound.

In all, the list said, the FBI retrieved 18 documents marked as top secret, 54 marked as secret, 31 marked as confidential — and 11,179 government documents or photographs.

On Thursday, a federal judge in Florida, Aileen M. Cannon, ordered the inventory list to be released during a hearing to determine whether to appoint a so-called special master to review the government records.

New York Times News Service