(a) No person shall be excused from attending and testifying or producing papers, documents, records, or other items of evidence, before houses of the general assembly, or any such committee of either or both houses, in obedience to a subpoena of those bodies or any such committee, on the ground or for the reason that the testimony or evidence, documentary or otherwise, required of such person, may tend to incriminate or subject such person to a penalty or forfeiture; but the testimony so given shall not be used in evidence against such person in any criminal prosecution in the courts of this state, seeking conviction for any offense about which such person has been required to testify, except for perjury in giving the testimony.

(b) No such person so testifying, or producing such evidence, documentary or otherwise, in obedience to such subpoena shall thereafter be liable to indictment, prosecution or punishment for or on account of any transaction, matter or thing, concerning or with reference to which such person may testify, or produce evidence, documentary or otherwise, before those bodies or either of them or before any such committee, in obedience to any subpoena issued by them or either of them, in the course of such inquiry and investigation pending before them or any of them. Such person may plead or prove the giving of testimony accordingly in bar of such indictment or prosecution; provided, that the above immunity from use of any such testimony or evidence, documentary or otherwise, against such person and witness, and the above immunity from indictment, prosecution or punishment of such person and witness, shall be claimed by such person and witness declining to answer the particular question or questions which such person may think has a tendency to incriminate such person, upon the expressly stated claim or objection that an answer or answers may tend to incriminate the witness.

(c) When, after making such claim and objection, the witness is nevertheless directed to make answer, and obeys such direction and makes answer accordingly, then the full immunity hereinbefore given and declared shall be possessed by such person and witness after being directed to make answer, notwithstanding the claim or objection that an answer may tend to incriminate the witness; provided, that any witness upon being called to testify or required to produce evidence, documentary or otherwise, before such bodies, or a committee of either or both of them, may be given the option of signing a waiver of all such immunity, and if witness shall sign the waiver, then the testimony and evidence, documentary or otherwise, given or produced by such witness, shall be admissible against such person, if otherwise competent and relevant, in any criminal prosecution brought against any such person and witness.