Quote Originally Posted by Super5
So how did they check if s/he was a woman or not? The old "feel 'her' up" gag? Seriously, though, this person must have been really desperate to win something if they tried to pass as a woman...
They probably did a blood test and checked his/her chromosome levels because there's a legal precedent. The Olympic committee has performed blood tests on athletes for years to test for steroid abuse. This allows them to do blood tests without any legal challenges.

But, like I said, a CAT scan would be easier, and more accurate. Taking the right hormone supplements could mask your chromosomes (to some degree), but nothing can change the fact that someone born as a man has no uterus.