It shall be the duty of the head of each state agency, commission, or board, or his designee, or any other official granted supervisory control for the expending of state funds to examine all applications for the reimbursement of personal funds expended by any employee of such agency, commission, or board for travel while conducting official business for state government. All such expenditures shall be necessary and reasonable for the efficient and effective operation of the agency, commission or board.
Va. Code § 2.2-2824