Okla. Stat. tit. 62 § 373
Upon the refusal, failure, or neglect of the proper officers of the state or of any county, city, town, or school district, after written demand signed, verified and served upon them by a number of registered voters of the state or such county, city, town, or school district equal to one hundred (100), or two and one-half percent (2 1/2%) of the registered voters living within the state or such county, city, town or school district, whichever is less, to institute or diligently prosecute proper proceedings at law or in equity for the recovery of any money or property belonging to the state, or such county, city, town, or school district, paid out or transferred by any officer thereof in pursuance of any unauthorized, unlawful, fraudulent, or void contract made, or attempted to be made, by any of its officers for the state or any such county, city, town, or school district, any resident taxpayer of the state or such county, city, town, or school district affected by such payment or transfer after serving the notice aforesaid and after giving security for cost, may in the name of the State of Oklahoma as plaintiff, institute and maintain any proper action which the proper officers of the state, county, city, town, or school district might institute and maintain for the recovery of such property; and the state or such county, city, town or school district shall in such event be made defendant. If a court of competent jurisdiction determines the claims to be meritorious, the contract shall be deemed void and the money or property, if previously transferred, shall be returned to the state, county, city, town or school district. The state, county, city, town or school district shall be liable to the resident taxpayer or taxpayers for reasonable attorney fees and court costs incurred in the prosecution of the action. If all claims stated by the resident taxpayers in the written demand are determined in a court of competent jurisdiction to be frivolous, the resident taxpayers who signed such demand and who are parties to the lawsuit in which such claims are determined to be frivolous shall be jointly and severally liable for all reasonable attorney fees and court costs incurred by any public officer or officers or any other person alleged in such demand to have paid out, transferred, or received any money or property belonging to the state, or such county, city, town or school district in pursuance of any alleged unauthorized, unlawful, fraudulent, or void claim paid or contract or conveyance made, or attempted to be made, by such officer or officers.
Okla. Stat. tit. 62, § 373