Every member of the grand jury must keep secret whatever he himself, or any other grand juror may have said, or in what manner he or any other grand juror may have voted on a matter before them; and such matters shall be subject to disclosure according to chapter 1, title 74, Idaho Code, but may, however, be required by any court to disclose the testimony of a witness examined before the grand jury, for the purpose of ascertaining whether it is consistent with that given by the witness before the court, or to disclose the testimony given before them by any person, upon a charge against such person for perjury in giving his testimony, or upon trial therefor.