Okla. Stat. tit. 74 § 316
The State Fire Marshal and the Assistant Fire Marshal shall each have power in any county in the State of Oklahoma to summons and compel the attendance of witnesses before them, or either of them, to testify in relation to any matter which by any of the provisions of this act is made a subject of inquiry and investigation and may require the production of any books, papers or documents deemed pertinent thereto by them, or either of them. Said State Fire Marshal, Assistant Fire Marshal are each hereby authorized and empowered to administer oaths or affirmations to any person appearing as witness before them and false swearing in any matter or proceedings aforesaid shall be the felony of perjury and shall be punished as such. Any witness who refuses to be sworn or refuses to testify or who disobeys any lawful order of the said State Fire Marshal, Assistant State Fire Marshal, or who fails or refuses, to produce any book, paper or document, touching on any matter under examination, or who is guilty of any contemptuous conduct after being summoned by them or either of them, to appear before them, or either of them, to give testimony in relation to any matter or subject under investigation as aforesaid, shall be deemed guilty of a misdemeanor and it shall be the duty of the State Fire Marshal, Assistant State Fire Marshal, or either of them to make complaint against said person or persons so refusing to comply with the summons or order of the said State Fire Marshal, or Assistant State Marshal, before any justice of the peace, police magistrate, or any court of record in the county in which said investigation is being had, and upon the filing of such complaint such court shall proceed in the same manner as other criminal cases and upon conviction of any such person guilty of violation of the provisions of this act, shall be fined in a sum of not exceeding Twenty-five Dollars ($25.00) and imprisonment until such fine is paid; provided, however, that any person so convicted shall have the right of appeal. Said State Fire Marshal and his subordinates or either of them shall have the authority at all times of day or night in the performance of the duties imposed by the provisions of this act, to enter upon and examine any building or premises where any fire has occurred and other buildings adjoining or near the same. All investigations held by or under the direction of the said State Fire Marshal, may, in his discretion be private, and persons other than those required to be present by the provisions of this act, may be excluded from the place where such investigation is held and witnesses may be kept separate and apart from each other and not be allowed to communicate with each other until they have been examined.
Okla. Stat. tit. 74, § 316