Human Rights Watch has accused the International Association of Athletics Federations of discriminating against female athletes with naturally high levels of testosterone and urged the governing body to scrap its hyperandrogenism rule.

From 1 November, female athletes who race between 400 metres and a mile and have at least five nanomoles of testosterone per litre (nmol/L) of blood will have to reduce that amount to within the usual female range for the hormone or race against men or other “intersex” athletes.