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Michael Frater And Kim Collins Training Session

MELBOURNE, AUSTRALIA - APRIL 05: Kim Collins of St Kitts and Nevis warms up for of a training session ahead of The 131st Stawell Gift, at Lakeside Stadium on April 5, 2012 in Melbourne, Australia. (Photo by Mark Dadswell/Getty Images)

Controversies at the 2012 London Olympic Games

The Olympic Games are a celebration of the human spirit and sporting excellence, but even the greatest sporting spectacle in the world has some of its sheen taken away by athletes who indulge in unfair practices including match-fixing and doping as well as expressing themselves by sending racist tweets. Here's a look at the controversies that have engulfed the 2012 London Olympic Games.