A New York Times report indicates that dozens of Russian Olympians at Sochi participated in a far-reaching, state-operated doping program, according to the then-director of Russia's anti-doping laboratory. Grigory Rodchenkov contends that he created a concoction of three drugs and liquor that he provided to at least 15 medal winners.
The testing agency and Russian intelligence services combined to swap out the athletes' tainted urine with clean urine taken months earlier. Rodchenkov estimated that as many as 100 samples were exchanged under the cover of darkness, and that none of the doping athletes were caught.
— Jay Busbee
Here's a rundown of the major doping scandals that have tainted sports through the years.