Hundreds of "top secret" and classified Australian government papers have been found in locked cabinets sold at a secondhand shop, national broadcaster ABC reported Wednesday as Canberra ordered an urgent probe.
The two filing cabinets were bought for "small change" from a store in the nation's capital that sells off ex-government furniture, the broadcaster said. The cabinets were locked and sold without keys, it added.
The ABC reported nearly all the documents are classified. The classifications include "top secret," "sensitive," ''Australian eyes only," and "cabinet-in-confidence."
The ABC has not said when the documents were found. But it has used them in recent weeks to report stories that have been embarrassing to the former administrations of Prime Minister Kevin Rudd and Abbott as well as a number of serving lawmakers.
The state-owned broadcaster said it had chosen not to report some documents on national security grounds.
They were unopened for several months until someone used a drill to get into the drawers, finding a trove of documents detailing almost a decade of government workings, the ABC said.
The documents cover Australia's intelligence priorities and counterterrorism planning. They detail missile upgrades, profiles of suspected militants and Australia's desire in 2010 for more Indonesian cooperation to stop asylum seekers reaching Australian shores in fishing boats, the ABC said.
The files include a report on the Australian Federal Police losing nearly 400 national security files in five years, and another about how 195 top secret documents were left behind in a senior minister's office after Labor lost the 2013 elections.
The documents also featured defense plans in the Middle East, Afghanistan conflict updates and intelligence on Australia's neighbors, the ABC reported.
Others detailed policy debates within the cabinets of previous Labor and Liberal-National coalition governments under former leaders Kevin Rudd, Tony Abbott and John Howard.
Prime Minister Malcolm Turnbull quipped on Tuesday before the ABC revealed its filing-cabinet source for one story that it appeared their reporters "have come across someone's bottom drawer in Canberra".
The ABC have broadcast a series of stories over the past few days, without declaring the source of the information.
It has also declined to say who found the documents or handed them over to the broadcaster.
The Department of the Prime Minister and Cabinet said Wednesday it had "initiated an urgent investigation" into how the filing cabinets were disposed.
Australian cabinet papers are usually not released to the public until two decades after they were created.
Rory Medcalf, head of the Australian National University's National Security College, described the discarded documents as "very weird and embarrassing" from a national security and political perspective.
Australia's allies, including the United States, "would be concerned, but I wouldn't overstate it," Metcalf said.
"This is not catastrophically damaging for national security in the sense that that something like the Snowden revelations must have been," he added, referring to the former U.S. National Security Agency contractor Edward Snowden disclosing a cache of classified material in 2013.