Australian secret service officers have seized hundreds of classified documents from Australian Broadcasting Corp. bureaus in three cities as part of a probe into how top-secret government papers were mistakenly sold along with two discarded filing cabinets.

The state-owned broadcaster and the government say Australian Security Intelligence Organization officers seized documents from ABC bureaus in Parliament House in the capital of Canberra and in the cities of Brisbane and Melbourne late Thursday.

Hours earlier, ASIO had provided document safes to the ABC offices to safeguard the files while lawyers negotiated over what to do with papers that include Cabinet secrets spanning almost a decade.

The ABC says the documents were seized as part of an agreement struck with the prime minister's department, which is investigating how the documents were discarded.