Cal. Government Code § 91000.5

An administrative action brought pursuant to Chapter 3 (commencing with Section 83100) alleging a violation of any of the provisions of this title shall not be commenced more than five years after the date on which the violation occurred. (a) The service of the probable cause hearing notice, as required by Section 83115.5, upon the person alleged to have violated this title shall constitute the commencement of the administrative action. (b) If the person alleged to have violated this title engages in the fraudulent concealment of the person’s acts or identity, the five-year period shall be tolled for the period of the concealment. For purposes of this subdivision, “fraudulent concealment” means the person knows of material facts related to the person’s duties under this title and knowingly conceals them in performing or omitting to perform those duties, for the purpose of defrauding the public of information to which it is entitled under this title. (c) If, upon being ordered by a superior court to produce any documents sought by a subpoena in any administrative proceeding under Chapter 3 (commencing with Section 83100), the person alleged to have violated this title fails to produce documents in response to the order by the date ordered to comply therewith, the five-year period shall be tolled for the period of the delay from the date of filing of the motion to compel until the date the documents are produced.