Cal. Lab. Code § 4753.5
In any hearing, investigation, or proceeding, the state shall be represented by the Attorney General, or the attorneys of the Department of Industrial Relations, as appointed by the director. Expenses incident to representation, including costs for investigation, medical examinations, other expert reports, fees for witnesses, and other necessary and proper expenses, but excluding the salary of any of the Attorney General's deputies, shall be reimbursed from the Workers' Compensation Administration Revolving Fund. No witness fees or fees for medical services shall exceed those fees prescribed by the appeals board for the same services in those cases where the appeals board, by rule, has prescribed fees. Reimbursement pursuant to this section shall be in addition to, and in augmentation of, any other appropriations made or funds available for the use or support of the legal representation.
Ca. Lab. Code § 4753.5