Okla. Const. art. II, § 27

Witnesses not excused from testifying - Immunity from prosecution. Any person having knowledge or possession of facts that tend to establish the guilt of any other person or corporation under the laws of the state shall not be excused from giving testimony or producing evidence, when legally called upon so to do, on the ground that it may tend to incriminate him under the laws of the state; but no person shall be prosecuted or subjected to any penalty or forfeiture for or on account of any transaction, matter, or thing concerning which he may so testify or produce evidence. All other provisions of the Constitution or the laws of this state in conflict with the provisions of this constitutional amendment are hereby expressly repealed. Amended by State Question No. 482, Legislative Referendum No. 188, adopted at election held on Dec. 7, 1971.