The domestic spy agency ASIO has taken possession of thousands of sensitive government documents found in a locked filing cabinet bought from a second-hand shop.
The ABC and the Department of the Prime Minister and Cabinet agreed on the securing and return of the documents on Thursday evening.
The national broadcaster said the transfer did not compromise the source of the cabinet files.
"This has been achieved without compromising the ABC’s priority of protecting the integrity of its source and its reporting, while acknowledging the Commonwealth’s national security interests," the ABC said in a statement.
ASIO officers took possession of the papers - which had previously been placed into safes in ABC offices - in Melbourne, Brisbane Canberra late on Thursday evening, according to the ABC.
When contacted by SBS News, an ABC spokeswoman would not make any further comment about the matter.
The Department of Prime Minister and Cabinet launched an urgent investigation on Wednesday after the ABC revealed it had obtained papers covering details of five federal government cabinet meetings over a decade.
About 1am on Thursday, ASIO officers brought a safe to the public broadcaster's bureaus at Parliament House and Brisbane so the documents could be kept securely.
The trove, some classified "top secret", was sold cheaply at a second-hand shop in Canberra, which stocked ex-government furniture.
The filing cabinets were unlocked with a drill months later.
Deputy Prime Minister Barnaby Joyce said the person responsible for losing the documents will have serious questions to answer.
"Obviously someone's had a shocker and the investigation will find out exactly how this happened," he told ABC radio on Wednesday.
Cabinet papers are legally supposed to remain secret for 20 years after their production.
The ABC said it had chosen not to publish many of the documents because of their classified nature.
- with SBS News
