The Constitution Protection Office (AH) is the successor of the National Security Office (NBH) that was one of the national security services established with independent professional management upon the legal grounds coming into force in the course of change of the political regime (Act X of 1990 on the temporary regulation of the special means and methods of secret services, and the Government Decree 26/1990 (II. 14.) on the temporary regulation of carrying out of national security duties).
Subsequent to the temporary regulations, the Act CXXV of 1995 on the national security services was passed by the Parliament. It regulates the scope of responsibilities and legal status of the civilian domestic intelligence, the rules of covert intelligence gathering, furthermore, the principles of national security activities and its parliamentary supervision.