Examination of witnesses.

Any officer making any enquiry referred to in section 2 may examine orally any person supposed to be acquainted with the matter under enquiry or any fact relevant thereto, and may reduce into writing any statement by the person so examined. Such person shall be bound to answer truly all questions relating to such matter put to him by such officer, other than questions the answers to which would have a tendency to expose him to a criminal charge or to a penalty or forfeiture. Any such statement against a person, unless it is taken in his presence and signed by the deponent, shall not be used in evidence against him in any judicial proceedings.