Cal. Gov. Code § 12410

The Controller shall superintend the fiscal concerns of the state. The Controller shall audit all claims against the state, and may audit the disbursement of any state money, for correctness, legality, and for sufficient provisions of law for payment. Whenever, in his opinion, the audit provided for by Chapter 4 (commencing with Section 925), Part 3, Division 3.6 of Title 1 of this code is not adequate, the Controller may make such field or other audit of any claim or disbursement of state money as may be appropriate to such determination.