The Controller shall conduct any additional audits which are necessary to carry out his or her duties and responsibilities under this code and the Government Code. Nothing in this chapter shall be construed to authorize any local educational agency, or any subcontractor or subrecipient, to constrain, in any manner, the Controller from carrying out any additional audits. However, to the extent that the required financial and compliance audits provide the Controller with the information necessary to carry out his or her responsibilities, the Controller shall plan additional audits as appropriate to avoid any unnecessary duplication of audit efforts. In performing these additional audits, the Controller shall, to the extent deemed appropriate under the circumstances, build upon the work performed during the required financial and compliance audit. The Controller shall not bill the school district or the county superintendent of schools for the costs of these additional audits.