Former NBA referee Tim Donaghy set off a firestorm of controversy in 2007. That summer, an FBI investigation found that Donaghy had placed tens of thousands of dollars worth of bets on games that he officiated.
Worse yet, he admitted that he made calls that affected the outcome of the game, so that he could manipulate the point spread and win his wagers.
Donaghy also went on to say that he was not the only NBA referee involved in such behavior, and that the league themselves sometimes ordered officials to extend playoff series to help increase TV ratings and ticket sales.
Commissioner David Stern has denied this charge, and while the furor surrounding this scandal has died down in recent months, it nonetheless called into question the integrity of an entire sports league.