Are you referring to Asafa Powell and Sherone Simpson?
If so, they were exonerated by the CAS. That is why their sentences were significantly reduced. This information is easily available if you use Google.
Statistically the "dirtiest" Event Group in Track and Field is the "middle/distance crew" if we are going by numbers of convictions. The "cleanest" Event Group is the "multi-events"; between the sexes the men are cleaner than the women.
What does being politically correct have to do with failing a drug test - I am a little confused.