Cal. Gov. Code § 12946

It shall be an unlawful practice for employers, labor organizations, and employment agencies subject to the provisions of this part to fail to maintain and preserve any and all applications, personnel, membership, or employment referral records and files for a minimum period of two years after the records and files are initially created or received, or for employers to fail to retain personnel files of applicants or terminated employees for a minimum period of two years after the date of the employment action taken. For the purposes of this section, the State Personnel Board is exempt from the two-year retention requirement and shall instead, maintain the records and files for a period of one year. Upon notice that a verified complaint against it has been filed under this part, any such employer, labor organization, or employment agency shall maintain and preserve any and all records and files until the complaint is fully and finally disposed of and all appeals or related proceedings terminated. The commission shall adopt suitable rules, regulations, and standards to carry out the purposes of this section. Where necessary, the department, pursuant to its powers under Section 12974, may seek temporary or preliminary judicial relief to enforce this section.