Prescription for Murder (1958)

In "Rx for Murder" and "Rx Murder" in the USA (and not "RX" in either country), American doctor Jethro Jones comes into a quiet English seaside resort to investigate the activities of its leading medical doctor, Henry Dysert. He learns from Miss Bettyhill, the town-gossip, and others that 'the good doctor' might not be all that good, since each of his three wives (only one at a time), Louise, Charlotte and Stella, had mysterious and tragic deaths. The non-gossiping townsmen had regarded the three deaths, each of which left Doctor Dysert in better financial shape, as unfortunate personal tragedies. Jason has only a short time to prove that Dysert was a multiple wife-killer, since Kitty Mortlock appears to be the next designated victim, and Jason has fallen in love with her himself.