South Africa’s Olympic and world 800m champion Caster Semenya has taken it upon herself to challenge the International Association of Athletics Federation’s (IAAF) female classification rule.

Her lawyers said on Monday that the athlete will take the case to the Court of Arbitration for Sport (CAS). She is faced with having to take medication to lower her unusually high levels of naturally-produced testosterone.

The higher levels are deemed by the IAAF to give her an unfair advantage.

Semenya’s case will be fought by law firm Norton Rose Fulbright.

The company said in a statement that the legal challenge will be filed at the CAS in Lausanne, Switzerland on Monday.

The statement read: ‘Ms Semenya, like all athletes, is entitled to compete the way she was born without being obliged to alter her body by any medical means.’

Semenya, 27, first came into the spotlight with a super quick 800m time at the African Junior Athletics Championships in Mauritius in 2009 and went on to post a breakthrough victory later that year over the same distance at the World Championships in Berlin.

The IAAF rule, which comes into force on 1 November, is not directly aimed at Semenya but she will be most affected by it.

‘I just want to run naturally, the way I was born. It is not fair that I am told I must change. It is not fair that people question who I am. I am Mokgadi Caster Semenya. I am a woman and I am fast,’ Semenya was quoted as saying in the Norton Rose Fulbright statement.