Cal. Gov. Code § 11180.5

At the request of a prosecuting attorney or the Attorney General, any agency, bureau, or department of this state, any other state, or the United States may assist in conducting an investigation of any unlawful activity that involves matters within or reasonably related to the jurisdiction of the agency, bureau, or department. This investigation may be made in cooperation with the prosecuting attorney or the Attorney General. The prosecuting attorney or the Attorney General may disclose documents or information acquired pursuant to the investigation to another agency, bureau, or department if the agency, bureau, or department agrees to maintain the confidentiality of the documents or information received to the extent required by this article.