In spite of anything else in this Act, the Secretary must not give to the Tribunal a document, or information, if the Minister certifies, in writing, that the disclosure of any matter contained in the document, or the disclosure of the information, would be contrary to the public interest:
(a) because it would prejudice the security, defence or international relations of Australia; or
(b) because it would involve the disclosure of deliberations or decisions of the Cabinet or of a committee of the Cabinet.