Where an offence under this Act has been committed by a company or an organisation or an institution, every person who, at the time the offence was committed, was in charge of, and was responsible to, the company, organisation or institution, as the case may be, for the conduct of its business or affairs, shall be deemed to be guilty of the offence and shall be liable to be proceeded against and punished accordingly:
     Provided that nothing contained in this section shall render any such person liable to any punishment provided in this Act if he proves that the offence was committed without his knowledge or that he exercised all due diligence to prevent the commission of such offence.
     Explanation.--For the purposes of this section, "company" means any body corporate and includes a firm or other association of individuals.