CANBERRA, Australia (AP) — The Australian government has launched an urgent investigation into the loss of thousands of classified documents that were sold with two second-hand filing cabinets.

Australian Broadcasting Corp. reported on Wednesday that the cabinets were sold by a Canberra furniture shop at a discount price because they were locked and no one could find keys.

The ABC has not identified the buyer who removed the locks with a drill and found thousands of Cabinet documents spanning more than a decade and four prime ministers, the most recent being Tony Abbott. Abbott was replaced in 2015 by the current Prime Minister Malcolm Turnbull.

The Department of Prime Minister and Cabinet says it has initiated an urgent investigation into the cabinet's disposal.

The ABC reports nearly all the documents are classified.