(1) Where an offence has been committed by a company, every person, who at the time the offence was committed was in charge of, and was responsible to, the company for the conduct of the business of the company, as well as the company, 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 sub- section shall render any such person liable to any punishment provided for the offence, if he has proved that the offence was committed without his knowledge or that he had exercised all due diligence to prevent the commission of such offence.