Lord Coe insisted he is the right man to guide athletics through its doping crisis, but was accused of lacking curiosity during a three-hour inquisition in which the embattled IAAF president offered as many questions as answers.
Coe gave evidence to the MPs from the culture, media and sport select committee investigating blood doping in athletics following recent revelations.
The former Olympic 1,500m champion says he has no regrets since being made president and is determined to navigate through the furore sparked when a World Anti-Doping Agency independent commission report detailed systematic, state-sponsored doping and related corruption in Russia.
Russia has since been suspended by the IAAF and its athletes could potentially miss the 2016 Olympic Games.
Coe, who became an IAAF vice-president in 2007, denied the world governing body had an "acceptance" of doping.
He was grilled over whether he had any concerns over predecessor Lamine Diack, who is currently under criminal investigation following allegations Russian athletes were protected after failing drugs tests.
Asked for his reaction to Diack being placed under investigation, Coe said: "Shock. Shock suffused with sorrow and anger."
Coe was aware of allegations about Diack's son, Papa Massata Diack, made in a documentary by German broadcaster ARD. Diack junior stepped down from his IAAF role in the wake of the broadcast.
Asked if he had spoken to Lamine Diack, then the IAAF president, about the allegations, Coe said: "No, because there were no allegations being made about the president."
Coe was then asked to "describe his lack of curiosity" and indicated it was down to a probe already being ongoing.
Athletics officials in Kenya are under investigation regarding allegations linked to Qatar's successful bid for the 2019 World Championships, but Coe refused to say if the investigation would widen to the whole bid.
The American city of Eugene was unsuccessful in its bid for 2019 but was awarded the 2021 event without it going to a vote.
Coe said it was a strategic decision to take the event to the United States, but Eugene is near the home of sportswear giant Nike which, until last week, employed Coe as an ambassador on a reported £100,000 a year.
Coe rebuffed suggestions of a conflict of interest, despite an email emerging last week which suggested he lobbied his predecessor over Eugene.
He described investigations into suspicious blood results as "a declaration of war on our sport" in August. He has since insisted he was only referring to stories which had tainted the reputation of clean athletes.
"I probably might have chosen different language," he said.