6. The Auditor-General shall in his audit make such examination as he may consider necessary to ascertain whether all reasonable steps have been taken —
(a)
to safeguard the collection and custody of public moneys or other moneys subject to his audit;
(b)
to ensure that issues and payments of moneys subject to his audit were made in accordance with proper authority and payments were properly chargeable and are supported by sufficient vouchers or proof of payment; and
(c)
to ensure that the provisions of the Constitution and of the Financial Procedure Act [Cap. 109] and any other written law relating to moneys or stores subject to his audit have been in all respects complied with.