Michael Phelps to lose his medals?

Michael Phelps, widely recognised as the greatest Olympian of all time, could reportedly be stripped of his four gold and two silver medals at the 2012 Olympics.

The American was seen posing in an advertising campaign for Louis Vuitton in pictures which surfaced on August 13 - even though regulation rules ban it.

According to Rule 40 of the International Olympic Committee: "No athlete was able to participate in non-Olympic marketing campaigns from July 18 to August 15, 2012".

Phelps, who could also be fined, has won 18 Olympic gold medals.