ISTANBUL, TURKEY - DECEMBER 14: Chad Le Clos of South Africa looks on prior to his Men's 50m Butterfly heat during day three of the 11th FINA Short Course World Championships at the Sinan Erdem Dome on December 14, 2012 in Istanbul, Turkey. (Photo by Clive Rose/Getty Images)

Cape Town – South African swimming champion Chad le Clos, who dramatically pipped US legend Michael Phelps to Olympic gold in 2012, is to tell his story in a book, his publisher said Wednesday.

The 20-year-old beat Phelps by five-hundredths of a second in the 200m butterfly at the London games last July.

The book will be titled “Unbelievable” which was his father Bert's joyous reaction to his son's win in an interview which became an Internet hit.

“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 be co-authored, will cover his life from childhood to present, including last year's Olympics.

The book will be published in mid-2014. – Sapa-AFP