The commissioner was fired after refusing to divulge secret police information on trade unions to the South Australian Parliament. The courts found that the commissioner's dismissal was justified because the South Australian Parliament was entitled to the information. The affair raises the question how far Commonwealth/State cooperation on security matters must interfere with a police commissioner's obligations to his own government. The authors contend that some cooperation is desirable. Most subversive activity is not directed against one level of government rather than another, but against the constitutional system which includes both. Federal and State cooperation in security measures requires some restrictions on the rights of a State government to demand information from its own police commissioner, but no State government can be expected to acquiesce in the determination of such restrictions either by the unilateral decision of a Federal agency or the commissioner's own opinion of his obligations. Federal and State governments should conclude formal agreements for the cooperation of State special branches with the Australian Security Intelligence Organization. Such agreements should set out rules governing the use made of information supplied by one agency to another and should spell out what rights either government has to be informed of security operations. Only such a clarification of the rules can ensure effective cooperation while safeguarding the legitimate interests of both Federal and State governments and protecting police commissioners from impossible conflicts of loyalty. Included in this article is a review, by State, of commissioners, the extent of their autonomy, and the mechanisms for holding them accountable to elected representatives. A table summarizes this information. Fifty-eight footnotes and references are provided.