
16. Charles Francis
Ben Johnson became a Canadian hero when he won gold in 1988. The sprinter broke the world record on his way to glory and global fame. However, the world came crashing down around him when he failed drug tests. Suddenly, he was a figure of notoriety.

His coach, Francis, introduced him to steroids for the first time. Francis had a pernicious influence on his athletes and encouraged them to take PEDs. In the end, it cost everybody dearly because the truth emerged. Francis died in 2010 as a disgraced figure (via The Guardian).