Mo. Rev. Stat. § 241.210
In all cases where swamplands have been or may hereafter be sold, which had been previously sold and patented by any county commission in this state, to a bona fide purchaser, it shall be the duty of the county commission of the county in which such sales were made, upon proper application of the subsequent purchaser, accompanied by the proper proof, showing the facts, to draw a warrant on the county treasury in favor of the person who paid the same, for the amount of such purchase money actually paid into the county treasury; provided, that such person in whose favor such warrant is drawn shall relinquish all interest and title in such land in favor of the county or the prior purchaser holding a prior patent to such lands.
§ 241.210, RSMo
RSMo 1939 § 12779