Okla. Stat. tit. 21, § 21-1367: Privilege of witness

No person shall be excused from giving evidence upon any

investigation or prosecution for any of the offenses specified in

this article, upon the grounds that such testimony or evidence might

tend to convict him of a crime. But such answer or evidence shall

not be received against him upon any criminal proceeding or

prosecution, except in a prosecution against him for perjury

committed in giving such testimony.