Police were investigating whether any Australian law was broken by the latest leaking of confidential documents by online whistle-blower WikiLeaks, the attorney-general said Monday.

Robert McClelland said he was not aware of a request from the United States to cancel WikiLeaks founder Julian Assange's Australian passport. A range of options were under consideration by Australian government agencies in response to the latest disclosure of classified U.S. material, he said.

McClelland told reporters there are "potentially a number of criminal laws" that could have been breached.

Defense Minister Stephen Smith said later that a cross-government committee was studying the documents to ascertain what damage could be done by their release.

"We need to take it ... step by step, but our starting and endpoint is essentially protecting Australia's national interest," Smith said in an interview on Sky News television. "This is an act which again one has no option but to absolutely condemn it. It potentially puts national security interests and it puts the safety and welfare of individuals at stake."

Australian Prime Minister Julia Gillard last week condemned the planned leaks as reckless and potentially harmful to national security interests.

Smith said the U.S. ambassador had told the Australian government and relevant ministers about the leaks ahead of their release.