US Anti-Doping chief Travis Tygart says Lance Armstrong can still do cycling a service by admitting his doping past.
Armstrong was stripped of his seven Tour de France titles earlier this year after a USADA report placed him front and centre of 'the most sophisticated, professionalised and successful doping programme the sport has ever seen.'
The Texan has remained almost completely silent on the subject, something that has disappointed Tygart.
"We gave him an opportunity to come in and be truthful," Tygart told the Guardian.
"That was probably the lowest point for me, because I really thought the change for the sport and the legacy of this effort could have been huge, far bigger, if he had embraced being a solution rather than an ongoing problem.
"I just know the power of an athlete in that predicament. We had 11 athletes come forward and their stories are what has allowed this to happen - they're very powerful.
"To be the one, with the reach and appeal he has, could have taken it to a whole new level as far as the good that could come from it is concerned. It would be as big as we've ever seen in terms of promoting the integrity and the values of the sport."
Tygart also criticised the role of the UCI in the scandal, especially their delay in affirming the USADA sanctions against Armstrong, who was also banned for life from the sport.
He continued: "Actions speak louder than words. They had an opportunity to support us from the beginning and not do a flip-flop and attack us in the press, attack our authority and jurisdiction.
"Then they had an opportunity to fully embrace the right outcome, which the entire world - including a number of corporate sponsors - embraced and not again justify or look for excuses for their failure.
"The justification that came out seemed to be full of excuses, not solutions going forward. It's very selfish. It's very self-interested, rather than being for a bigger purpose or vision. It's very defensive."