Cal. Welf. & Inst. Code § 11484

On request, all state, county, and local agencies shall cooperate with an investigator of an agency whose primary function is to detect, prevent, or prosecute public assistance fraud, by providing all information on hand relative to the location and prosecution of any person who has, by means of false statement or representation or by impersonation or other fraudulent device, obtained aid, or attempted to obtain aid for an individual under this chapter. That information is subject to confidentiality requirements under Chapter 5 (commencing with Section 10850) of Part 2. For purposes of this section, “information” shall not include taxpayer return information as defined in Section 19549 of the Revenue and Taxation Code, unless disclosure of this information is expressly authorized pursuant to Article 2 (commencing with Section 19501) of Chapter 7 of Part 10.2 of the Revenue and Taxation Code.