No civil or criminal proceedings shall be instituted against the Secretary to the Treasury, Deputy Secretary to the Treasury, Director-General or any employee of the Office or any member of the Committee as the case may be, for any act which in good faith is done or purported to be done or omitted to be done by him under this Act pursuant to and in the course of the exercise, performance and discharge of the powers, duties and functions on behalf of the Office, if he proves that he acted in good faith and exercised all due diligence, reasonable care and skill.