Sebastian Coe faces fresh questions about what he knew of corruption within athletics before he was elected IAAF president.
Britain's parliamentary Culture, Media and Sport select committee heard evidence Tuesday that "undermined" his previously made claims of ignorance, and its chairman said he would be calling Coe to appear again.
Coe told members last December that he was unaware of any specific allegations about the extent of Russian doping, or that senior IAAF officials were extorting money from Russian athletes to bury positive drug tests, until German broadcaster ARD broke the story in 2014.
But Dave Bedford, the former London Marathon race director and chairman of the IAAF's road racing commission, who appeared before the committee Tuesday, said that he had called and emailed Coe to warn him about the scandal in August 2014; he also claimed they had spoken about a related matter two weeks before the broadcast.
Coe had told members of parliament he simply forwarded Bedford's emails to the IAAF's new ethics board without reading them properly or opening the attached documents.
Bedford said he was "very surprised and quite disappointed" at the time to hear Coe say that.
In summing up Bedford's new evidence to the committee, conservative member of parliament Nigel Huddleston said it was clear his answers had "undermined" Coe's version of events.
However, Englishman Bedford, a former world 10,000 metres record holder, refused to say if he believed Coe's claim that he had not read his emails, despite being pressed on the subject.
In response to one such question, Bedford said: "I don't think it matters if I believe him or not. I was surprised that he said that and that goes some way to answering that question."
Asked for a personal view on why Coe may have chosen to remain, in committee member John Nicolson's words, "wilfully ignorant" of what was happening at the IAAF, Bedford said he thought his compatriot had decided the best way he could help save athletics was to get elected.