IAAF deputy general secretary Nick Davies has stepped aside while an investigation takes place over a plan to delay naming Russian drug cheats.
In an email to Papa Massata Diack, a former IAAF marketing consultant, before the 2013 World Championships in Moscow, Davies wrote about the need to discuss "Russian skeletons in the cupboard" with the anti-doping team.
The Englishman said to the son of Lamine Diack - the former president of athletics' ruling body - that "we need to be smart" about releasing names.
In a statement released on Tuesday, Davies said: "I have decided to step aside until such time as the Ethics Board is able to review the matter properly and decide if I am responsible for any breach of the IAAF Code of Ethics.
"What has become apparent is that I have become the story."
Davies denied any wrongdoing and explained he had shown emails sent to Papa Massata Diack in 2013 and statements to the IAAF Ethics Board.
The email which had been obtained by the BBC contains a "very secret" five-point plan and was sent on 19 July, 22 days before the start of the 2013 World Athletics Championships.
The IAAF announced sanctions against 16 Russian athletes in the four months following the Moscow event, in which Russia topped the medals table.
Last month, they became the first country to be banned from international competition because of doping after an independent report uncovered systemic, state-sponsored cheating.