Sebastian Coe, IAAF's President, attends the IAAF press conference in Monaco, November 26, 2015. [Photo/Agencies]

"We can prepare a special dossier on IAAF testing which will show that one of the reasons why these Russian athletes come up positive is that they get tested a lot."

The email also suggested that Coe, then an IAAF vice-president, might be able to use his political influence in Britain to minimise the damage any doping revelations might do, and sought ways to fend off negative stories in the British media.

Davies said on Monday that the mail was merely "brainstorming for a media strategy" and that he had done nothing wrong.

Massata Diack on Tuesday denied any involvement in bribery or corruption and said his father was also innocent.

The IAAF said on Monday that Coe would not comment on an email he knew nothing about.