Notwithstanding anything contained in any law for the time being in force in a prosecution for an offence for the contravention of a direction issued under sections 54, 55, 56, or 63 on the production of an authentic copy of the order, it shall, until the contrary is proved and the burden of proving which shall lie on the accused, be presumed,—

(a) that the order was made by the authority competent under this Act to make it;

(b) that the authority making the order was satisfied that the grounds on or the purpose for which it was made existed and that it was necessary to make the same; and

(c) that the order was otherwise valid and in conformity with the provisions of this Act.