(1) The Director General shall have the superintendence of all matters relating to the sales tax, subject to the direction and control of the Minister.

(2) Subject to the general direction and supervision of the Director General, all officers of Customs and Excise appointed under section 3 of the Customs Act 1967 and holding the rank of Superintendent or any rank higher than that of Superintendent, shall have and exercise all powers conferred on the Director General by or under this Act, other than those conferred by section 15 (5).

(3) It shall be the duty of any proper officer to enforce, and ensure due compliance with, the provisions of this Act, and to make all due enquiries in relation thereto.

(4) Every person employed on any duty or service relating to the sales tax by the order or with the concurrence of the Director General (whether previously or subsequently expressed) shall be deemed to be the proper officer for that duty or service; and every act required by law at any time to be done by, or with any particular officer nominated for such purpose, if done by or with any person appointed by the Director General to act for such particular officer, shall be deemed to be done by or with such particular officer.