(3)No person shall be appointed to be, or authorised to exercise the powers of, a certifying surgeon, or, having been so appointed or authorised, continue to exercise such powers, who is or becomes the owner, agent or manager of a mine, or is or becomes directly or indirectly interested therein, or in any process of business carried on therein or in any patent or machinery connected therewith, or is otherwise in the employment of the mine.
