(1)  Where this Act requires anything to be done by the owner, importer or exporter of any goods, it may be done on his behalf by his agent.

   (2)  Any such thing done by an agent of the owner, importer or exporter of any goods shall, unless the contrary is proved, be deemed to have been done with the knowledge and consent of such owner, importer or exporter, so that in any proceedings under this Act, the owner, importer or exporter of the goods shall also be liable as if the thing had been done by himself.

   (3)  When any person is expressly or impliedly authorised by the owner, importer or exporter of any goods to be his agent in respect of such goods for all or any of the purposes of this Act, such person shall, without prejudice to the liability of the owner, importer or exporter, be deemed to be the owner, importer or exporter of such goods for such purposes ¹[including liability therefor under this Act]:

   Provided that where any duty is not levied or is short-levied or erroneously refunded on account of any reason other than any wilful act, negligence or default of the agent, such duty shall not be recovered from the agent unless in the opinion of ²[Assistant Commissioner of Customs or Deputy Commissioner of Customs] the same cannot be recovered from the owner, importer or exporter.