Adolph Kiefer, left, the oldest living American Olympic gold medallist, has died at the age of 98 ©USA Swimming

Swimmer Adolph Kiefer, the oldest living American Olympic gold medallist, has died at the age of 98.

Kiefer won the 100 metres backstroke title at the Berlin 1936 Games aged just 17.

He was inducted into the inaugural class of the International Swimming Hall of Fame in 1965.

"Adolph Kiefer embodied swimming and lived it every day of his life," said USA Swimming's interim executive director Mike Unger.

"Adolph was so passionate about swimming and exuded it to everyone. 

"When you met him, he made you feel so special and he was amazing to be around."

Quadruple Olympic champion Matt Grevers receives his gold medal from Adolph Kiefer at the 2012 US Olympic Swimming Team Trials ©Getty Images
Quadruple Olympic champion Matt Grevers receives his gold medal from Adolph Kiefer at the 2012 US Olympic Swimming Team Trials ©Getty Images

In 1944, Kiefer entered the United States Navy and was appointed to set up a safety curriculum at a time when numerous lives were lost to drowning.

He pioneered the "victory backstroke" technique that taught sailors to breathe more easily on their backs, which was credited with preventing thousands of deaths in the final years of the Second World War.

The method was eventually adopted by the American Red Cross.

Kiefer founded a swim equipment company in 1947 which included several performance and safety products.

His innovations included the first nylon swimsuit, as well as lane lines, starting blocks and lifeguard equipment.