The ABC has returned top secret cabinet files to ASIO

Gary Friedman/Los Angeles Times via Getty Images

The ABC returned up to 1,500 top secret cabinet documents to ASIO overnight.

The decision followed negotiations between the broadcaster and the Department of Prime Minister and Cabinet following assurances that their source would be protected.

The ABC obtained highly classified cabinet documents spanning five governments over nearly a decade, after the papers found in filing cabinets on sale in a second-hand store in Canberra.

Yesterday ASIO officers locked the files away in safes so only the government agency and the ABC had access to them while they came to an agreement.

The Australian Federal Police has accused the ABC of knowingly publishing a story based on “incomplete and outdated” documents, and Kevin Rudd is suing the broadcaster for publishing a story on the Labor government’s home insulation scheme from leaked Cabinet documents.

The Department of Prime Minister and Cabinet has launched an investigation into the national security breach.

Read more on what’s in the files here.