Olympic chief Thomas Bach said on Saturday he had sympathy for Caster but respected the Court of Arbitration for Sport (CAS)’s decision that means the South African athlete will have to reduce her testosterone levels to compete.

Semenya won gold in the 800 meters at the last two Olympics but Wednesday’s CAS ruling means she will have to artificially reduce her levels of the hormone to defend her titles in Tokyo next year.

“First of all I must say I have a lot of sympathy for Caster Semenya over this decision,” the International Olympic Committee (IOC) president said at the Australian Olympic Committee (AOC) annual general meeting.

“Having said this, the issue as such is extremely complex. It has scientific impact, it has ethical impact, it impacts on ‘fair play’ in competition so it’s extremely delicate and it’s extremely difficult to do justice to all these (elements)”.

Bach said an IOC working group would examine the full CAS ruling once it was available, including recommendations from the panel of judges on how the rules should be implemented.

“What the IOC have been doing is trying to assist the international federations because it is they who have to take the decision because it is their rules”.

“The IOC respects CAS decisions, as we always do … but from a human point of view, yes, I have sympathy for her.”

The governing International Association of Athletics Federations (IAAF), who control the rules of competition in track and field at the Olympics, have imposed the conditions on female athletes with differences in sexual development (DSDs).

They cover track events ranging from 400 meters to a mile and Semenya has already indicated that she will not take medication to reduce her levels of testosterone, which increases muscle mass, strength and haemoglobin.

The World Medical Association (WMA) on Friday called on its members not to implement the regulations, saying there was “weak evidence” that they were necessary and that they should be scrapped.

“This is why we have this working group, where there are also medical experts,” Bach added.

“They try, as we always try in these situations, to come to what scientists call a consensus. This is what they are working on. I am not a medical expert so I cannot comment on the (WMA) statement. I have to rely on the experts.

“It is not only scientific, it is not only ethical, it is not only sport, it is also highly emotional. I’m afraid for these experts it will be very difficult to find a solution that brings together all these arguments.”

Semenya’s legal team have said they are considering appealing the CAS ruling.