Piotr Malachowski won the second Olympic silver medal of his career at Rio 2016.

The reigning World and European champion matched his second place finish from Beijing 2008, in the men's discus competition. Malachowski finished 82-centimetres behind Germany's Christoph Harting. 

Despite winning the silver medal, the 33-year-old decided to put the medal up for auction. He planned to give the money raised to a three-year-old boy suffering from eye cancer. The money would allow the child have potentially sight-saving surgery in New York. 

Malachowski ended the auction early when a substantial bid was made by Dominika and Sebastian Kulczyk. The brother and sister are among the richest people in Poland, having inherited their late father's fortune.

"My Silver Medal today is worth much more than a week ago", the discus star added on Facebook, when he revealed the auction had ended. 

Malachowski's generosity means his silver medal is certainly one of the most valuable Olympic medals of all time.