Mo. Rev. Stat. § 311.820
The supervisor of liquor control of the state of Missouri and his agents and inspectors, members of the Missouri state highway patrol, and every sheriff and deputy sheriff in the state of Missouri may inspect and search any vehicle, with or without a search warrant, which he has probable cause to believe is being used in violation of the terms of this statute; provided, however, that any evidence found by any such officer while inspecting or searching any vehicle pursuant to the provisions of sections 311.410 to 311.460 may be used in any prosecution for the violation of sections 311.410 to 311.460; in any proceeding seeking to have any property seized in such search declared contraband under the provisions of sections 311.410 to 311.460, 311.580 and 311.820 to 311.850, but any such evidence shall not be used in any other proceeding whatsoever, civil or criminal.
§ 311.820, RSMo