Next month the CAS is expected to rule on new evidence presented by the IAAF showing that high testosterone levels could shave around 2.5 seconds of an athlete’s time. There is typically less than two seconds between runners in 800m heats.

However sports science experts believe the court will refuse to take action for fear of opening themselves up to claims over other naturally occurring advantages, and accusations of sexism.

John Brewer, Professor of Applied Sports Science at Queen Mary University in Twickenham, said: “There is a reason that testosterone is a banned substance, it has an anabolic affect and increases muscle strength and power, so someone with more of it is likely to have more speed. And that’s clearly an advantage. It’s not a level playing field.

“But what can you do about it? Do you ban them? Do you have a cut off point? Do you have a separate category? The problem is there will always be athletes who are at the top of a range of physiological values whether it is oxygen uptake, or capillary density, or the ability tolerate high levels of lactic acid.

“Do you ban all Kenyan athletes because they train at high altitude and so can use oxygen more efficiently? “Testosterone levels is just one of many variables that impact performance. And it can work both ways. Someone with more testosterone generally gains more muscle mass and weighs more, so it can be like running with two extra bags of sugar.