In a resignation form, Cornelius addressed Lord Coe over the controversial new rule which would see the permitted natural testosterone level dropped from 10 nmol/L to five. 

"Sadly, I cannot in good conscience continue to associate myself with an organisation which insists on ostracising certain individuals, all of them female, for no reason other then being what they were born to be," Professor Cornelius wrote.

He finished the letter saying, "I do hope that there are offers who are in some way involved with the IAAF and who have the courage of conviction to take a strong stand against this injustice the IAAF will perpetrate against certain female athletes."

The IAAF funded study has not been peer-reviewed and has been discredited since it was released. 

The study is meant to show a direct link between hyperandrogenism and performance in selected track and field events.

However, despite their results showing those with the condition enjoying a greater advantage in the pole vault and hammer throw were not included in the 'restricted events' category.