Caster Semenya could be forced to undertake hormone therapy for future Olympics

Study shows performance-boosting effects of testosterone in female athletes, reopening controversial debate about intersex and hyperandrogenous competitors

• Using testosterone to categorise male and female athletes isn't perfect, but it's the best solution we have

Caster Semenya, the Olympic 800m champion, may be banned from competing at future Games unless she undergoes hormone replacement therapy (HRT) or even surgery in the wake of a landmark study into athletes with raised testosterone levels which has just been published.

The International Association of Athletics Federations, the world governing body, commissioned research which has produced the most conclusive evidence yet that female athletes with very high levels of naturally occurring testosterone receive significant performance-enhancing benefits in competition.