Sebastian Coe's chief of staff Nick Davies has stepped aside while the IAAF ethics committee investigates reports he tried to delay the identification of Russian drug cheats.
In the run-up to the 2013 world athletics championships in Moscow, Davies sent an email to the son of Lamine Diack - the former president of the sport's governing body the IAAF.
In it, Davies reportedly appeared to look to minimise the impact of naming Russian athletes who had failed drugs tests and is facing allegations of unethical behaviour.
He and Diack's son, Papa Massata Diack, who worked as a marketing consultant for the IAAF, allegedly discussed a "special dossier" that could be prepared to limit the impact.
Papa Massata Diack was one of the organisation's officials alleged to have covered up doping offences.
His father is the focus of a police investigation amid allegations he took money to cover up positive drugs tests by Russian athletes.
French newspaper Le Monde has obtained a copy of Davies' email.
The email also allegedly suggests CSM, the sport agency chaired by Coe since January 2013, could help the IAAF in an unofficial PR campaign as it could "benefit from Seb's political influence in the UK".
Davies is also reported to have said in the email he needed to understand "what Russian 'skeleton' we have still in the cupboard regarding doping".
Davies has denied any wrongdoing.
In a statement, he said: "As director of IAAF communications it was one of my responsibilities to manage and promote the reputation of the IAAF.
"My email to the IAAF's then marketing consultant Papa Massata Diack, less than a month before the start of the Moscow World Championship, was brain storming around media handling strategies to deal with the serious challenges we were facing around the image of the event.
"No plan was implemented following that email and there is no possibility any media strategy could ever interfere with the conduct of the anti-doping process.
"I did not discuss these ideas with CSM and there has never been any agreement between the IAAF and CSM for any PR campaigns.
"CSM has never worked for the IAAF in any capacity since Sebastian Coe joined the company."
Download the brand new OffTheBall App in the Play Store & App Store right now! We've got you covered!
Subscribe to OffTheBall's YouTube channel for more videos, like us on Facebook or follow us on Twitter for the latest sporting news and content.
