Some of the inner workings of the past five federal governments have been revealed publicly, but perhaps the most bizarre twist is how it happened.
The ABC has obtained highly classified documents found in the drawers of two filing cabinets purchased at a second-hand sale of former government furniture in Canberra.
It is being described as one of the biggest breaches of parliamentary security in Australian history.
Some of the documents are classified For Australian eyes only.
Among the more serious revelations is that almost 200 top-secret national-security documents, including Middle East defence plans and updates on the war in Afghanistan, were left behind.
They were meant to be destroyed when Labor lost the 2013 election but, instead, were left in the office of South Australian senator Penny Wong.
Also revealed were plans by former immigration minister Scott Morrison to purposely delay the visa process for asylum seekers.
And, further, the leak reveals former prime minister Kevin Rudd was warned about critical risks around the later failed home-insulation scheme.
Usually, such Cabinet documents are only made public 25 years later.
The head of the Department of the Prime Minister and Cabinet has ordered an urgent investigation into the breach.
