Okla. Stat. tit. 12, § 411

No testimony given by a witness before the House of Representatives or the Senate, or before any committee established by a Resolution of the House, or Senate, or Concurrent Resolution of the two Houses of the Legislature, shall be used as evidence in any criminal proceeding against him in any court, except in a prosecution for perjury committed in giving such testimony. But an official paper or record produced by him is not within the privilege.