California Code, Business and Professions Code - BPC § 18857

The commission, the executive officer, or authorized representative shall have the power to order a promoter to withhold 10 percent of the total purse payable to a contestant if the manager of the contestant does not present an itemized statement of expenses incurred in connection with the contest.  The money so withheld shall be paid to the commission and held in trust for payment to the contestant or his or her manager, upon presentation by the manager to the commission of the itemized statement of expenses.