Mo. Rev. Stat. § 49.500
Whenever any fifty resident, solvent and responsible taxpaying citizens of any county in the state shall have good reason to believe, and do believe, that any contract made and entered into by the county commission, with any person or corporation, affecting or concerning any public building, lands, moneys or property of the county in any manner whatever, or any extension of any such contract, was not made and entered into in good faith, or for a just consideration, and with due regard for the best interest of the county, or that any such contract previously entered into has not been carried out by the parties thereto in good faith and according to the terms of any such contract, they may bring a suit in the circuit court of any such county, praying that the matter may be inquired into, and thereupon the circuit court shall make a full investigation of the matters alleged, and shall have power to set aside, reform or cause to be enforced any such contract, or any extension of any such contract, as the court shall deem best under the law and the facts. Should the petitioners fail to sustain their petition, they shall pay the costs; and all such proceedings shall be governed by the law relating to civil practice in circuit courts. The said petition shall be filed in the office of the clerk of the circuit court of said county; and thereafter the death, removal or disability of any one or more of such petitioners or plaintiffs shall not abate or affect the said suit.
§ 49.500, RSMo
Effective 1/1/1985