This is quite an interesting article
"As documented by South African sports scientist Ross Tucker recently in one of his excellent blogs, back in 2009 the previously unheard of 18-year-old Semenya sensationally won the womens 800 metres at the World Championships in Berlin in a time of 1.55.45, one of the fastest times in history. She was recognised as potentially having high testosterone as a result of being intersex, and was investigated for that."