Except as otherwise provided, every officer or agent of the Virgin Islands who receives public money which he is not authorized to retain as salary, pay or emolument, shall render his accounts monthly. Such accounts, with the vouchers necessary to the correct and prompt settlement thereof, shall be sent to the bureau to which they pertain, and, after examination there, shall be passed to the office of the Government Comptroller of the Virgin Islands for settlement. In case of nonreceipt at the office of the Government Comptroller or proper bureau of any accounts within a reasonable and proper time thereafter, the officer whose accounts are in default shall be required to furnish satisfactory evidence of having complied with the provisions of this section. Nothing in this section, however, shall be construed to restrain the heads of any of the departments from requiring such other returns or reports from the officer or agent, subject to the control of such heads of departments, as the public interest may require.