Prime Minister Julia Gillard has again been unable to name any Australian laws broken by the controversial WikiLeaks website or its founder Julian Assange.

Western governments are increasingly calling for Mr Assange to be stopped as WikiLeaks continues to publish more than 250,000 confidential documents from the United States State Department.

But asked directly what Australian laws had been broken by either WikiLeaks or Mr Assange, Ms Gillard said the Australian Federal Police were investigating.

"The foundation stone of it is an illegal act," Ms Gillard told reporters today.