Davies, a close aide to IAAF chief Sebastian Coe, his wife Jane Boulter-Davies and medical manager Pierre-Yves Garnier have all been sidelined for 180 days from June 10.
"There is no greater priority for the IAAF right now than to get to the truth of the allegations that have been made against the sport. These particular facts were made public in December 2015 and relate to allegations of a breach of the IAAF Code of Ethics," an IAAF statement said.
The statement added that each of the persons provisionally suspended "enjoys the presumption of innocence until the outcome of the investigation and the determination of disciplinary charges, if any, brought against them."
The allegations stem from an email sent by Davies to the son of Lamine Diack - whom Coe succeeded as IAAF president last August - before the 2013 World Athletics Championships in Moscow which outlined a plan to delay naming Russian cheats to avoid bad publicity.