Olympic 200m butterfly champion Chad le Clos, whose brother nicknamed him the Phelps Slayer after the South African pipped Michael Phelps in the American's signature event at London 2012, is to tell his story in a book that his publisher hopes to have ready by summer 2014.

The 20-year-old, who beat Phelps by 0.05sec - 1:52.96to 1:53.01 - in a week that saw the American rocket to an all-time record of 18 gold and 22 Olympic medals in all before waving goodbye to the sport, is to call his book "Unbelievable".

That word was the first uttered by Chad's dad Bert, going wild up in the stands. 

"I'm aiming for it to be an inspiring read that will motivate the reader to know that nothing is impossible!" Le Clos said in a statement released by Penguin Books SA. The publisher said the book, which will have a ghost writer/co-author, will cover his life from childhood to present, including the events of London 2012 and his work with coach Graham Hill.