Lord Coe, the head of world athletics, will be recalled by the Culture, Media and Sport select committee, after MPs heard evidence that “undermined” his comments to them in December 2015.
Coe told the committee he was unaware of specific cases of corruption before they became public in December 2014.
But former athlete Dave Bedford said he contacted Coe about Russian athlete Liliya Shobukhova in August that year.
Bedford added he spoke to Coe about a related matter on 21 November 2014.
Allegations of state-sponsored doping by Russian athletes, and cover-ups involving officials at the sport’s world governing body the IAAF, were revealed in a documentary by German broadcaster ARD on 3 December 2014.
That is when Coe, who was elected IAAF president in August 2015, says he became aware of specific allegations.
Bedford, 67, said he was “very surprised and quite disappointed” to find Coe had not opened emails sent in August 2014, which provided details of alleged extortion from marathon runner Shobukhova, who was given a doping ban in 2014.
Coe, in his evidence to the committee, said he forwarded Bedford’s emails to the IAAF’s then recently formed ethics board, without reading them or opening the attachments.
Damian Collins, chair of the select committee, said he wanted Coe to come back before the committee because Bedford’s evidence “raised clear and important questions” about Coe’s knowledge of the allegations, while Conservative MP Nigel Huddleston said the answers “undermined” the former Olympic champion’s version of events.
In response, the IAAF said former London Marathon race director Bedford “offered nothing new” to the inquiry, and Coe has “no further information he can provide”.
Collins then issued a further statement, saying Bedford’s evidence “casts some doubt” on when Coe learned of specific allegations.
He added: “There are also questions about why Lord Coe didn’t do more to make himself aware of the issues that were contained in the allegations that Bedford sent him.”
However, Coe may not have to attend a further committee hearing. While select committees have the power to compel people to attend hearings and give evidence, MPs and members of the House of Lords – such as Lord Coe – are exempt from this rule.
Bedford agreed with the committee it was “strange” Coe had not opened his email attachments, and said he had no doubt the double Olympic champion knew about the Shobukhova case when they met in November 2014.
However, Bedford – a former 10,000m world record holder – also defended Coe, describing him “as someone within the IAAF who I could trust”.
When asked to explain why Coe did not follow up on the email, Bedford suggested he may have decided the “best way he could help the sport was to make sure he got elected as president”, as otherwise there was “no future” for athletics.
“In my opinion, looking at all the other alternatives, Seb Coe is the only chance athletics has to get over this difficult period,” added Bedford.