Mo. Rev. Stat. § 535.070
If any person purchases lands or tenements occupied at the time of such purchase by any tenant, lessee or sublessee, who shall, at any time thereafter, fail to pay rent to such purchaser, the person purchasing such property shall have the right, upon such failure, to commence proceedings before an associate circuit judge to recover rent and possession, under the terms of the prior owner's lease, for unpaid rent accruing after the transfer of title. The right to commence proceedings pursuant to this section shall exist regardless of whether the transfer was by private foreclosure, tax or judicial sale, or by any other means. The provisions of chapter 441 and this chapter shall apply.
§ 535.070, RSMo
RSMo 1939 § 2999, A.L. 1945 p. 1107, A.L. 1997 H.B. 361