(4)If any order made under this rule is contravened in respect of any premises, place, vehicle or vessel, the occupier of the premises or place, the person in charge of the vehicle, or the master of the vessel, as the case may be shall, without prejudice to any proceedings which may be taken against any other person, be deemed to have contravened the provisions of this rule:Provided that in any proceedings which by virtue of this sub-rule are taken against any person in respect of a contravention of such an order on the part of another person, it shall be a defence for the accused to prove that the contravention or non-compliance occurred without his knowledge and that he exercised all due diligence to secure compliance with the order.
