He was the husband of Reni Erkens and the father of Ernst-Joachim Küppers.

Thinking Kuppers was likely to win the 100 metre backstroke at the 1934 European Championships in Magdeburg, Hitler commissioned a large bronze eagle trophy for the race.

This weighed over 50 kilograms (110 lb) and stood nearly 1 metre (3 ft 3 in) high.

When John Besford of England won the race, Hitler refused to present the trophy as intended and left the stadium, leaving one of his officials to present it instead to Küppers’ rival.

This biographical article related to a German swimmer is a stub.