At the 1956 Olympics, only a 100-metre backstroke event existed, in which there were 25 competitors. Theile won his heat to qualify second fastest for the semifinals behind Monckton, who set an Olympic record in his heat. After some officials had questioned his turning style during the heats, Theile refused to give a demonstration to the judges as his team manager had previously promised them. He used a conventional in the semifinals as did the others, coming second to Monckton to progress to the final. In the final Theile made a good start and seized the lead from the start, never relinquishing it to win by more than a metre and a half from Monckton, setting a new world and Olympic record.