(CNN) -- A Lance Armstrong representative tried to make a donation of about $250,000 to the U.S. Anti-Doping Agency before the agency launched the investigation that led to the cyclist being stripped of his Tour de France titles, the chief of the USADA said.
"I was stunned," Travis Tygart, the head of the anti-doping agency told "60 Minutes Sports'' about the alleged 2004 offer. ''It was a clear conflict of interest for USADA. We had no hesitation in rejecting that offer.''
Armstrong attorney Tim Herman said there's no truth to the story.
"He never made any such contribution or suggestion," Herman said in a statement e-mailed to CNN Wednesday.
Annie Skinner, a spokeswoman for the USADA, told CNN that Tygart's quotes, released by "60 Minutes Sports,'' were accurate.
The new accusation is another chapter in the twisting tale of Armstrong, a one-time hero to many who has now fallen in disgrace.
Armstrong will give his first television interview since being stripped of his Tour de France titles to Oprah Winfrey, her network announced Tuesday.
A news release from the Oprah Winfrey Network said the 90-minute "no-holds-barred" interview will air at 9 p.m. ET January 17 and will be simulcast on Oprah.com.
Winfrey will ask the cyclist to address the U.S. Anti-Doping Agency's report, which said there was overwhelming evidence Armstrong was directly involved in a sophisticated doping program, the statement said.
The International Cycling Union, which chose not to appeal the USADA's lifetime ban, stripped Armstrong of his record seven Tour victories in October.
The World Anti-Doping Agency also agreed with the sanctions, which means Armstrong may not compete in sports governed by WADA code.
Before the ban, he was competing in Ironman triathlons and had won two of the five events he had entered. Since the ban he has entered two non-sanctioned events.
According to his Twitter feed, Armstrong has been biking, running and swimming in Hawaii. The Winfrey interview will take place at Armstrong's home in Austin, Texas.
The New York Times reported last week that Armstrong, 41, was contemplating publicly admitting he used illegal performance-enhancing drugs. Such an admission might lead toward Armstrong regaining his eligibility.
One of his attorneys denied Armstrong was in discussion with the two anti-doping agencies.
Dan Wuori, a writer at cycling publication Velo Magazine, said Armstrong may reveal a lot during the Oprah interview.
"I think what we are seeing here is the beginning of Lance's effort at redemption," Wuori said. "More and more continues to come out about Armstrong. This seems like an effort of Armstrong to get ahead of the story and control the narrative."
Armstrong has repeatedly and vehemently denied that he used banned performance-enhancing drugs as well as illegal blood transfusions during his cycling career.
Armstrong has been an icon for his cycling feats and celebrity, bringing more status to a sport wildly popular in some nations but lacking big-name recognition, big money and mass appeal in the United States.
He fought back from testicular cancer to win the Tour from 1999 to 2005. He raised millions via his Lance Armstrong Foundation to help cancer victims and survivors, an effort illustrated by trendy yellow "LiveSTRONG" wristbands that helped bring in the money.
But Armstrong has long been dogged by doping allegations, with compatriot Floyd Landis -- who was stripped of his 2006 Tour de France title after failing a drug test -- making a series of claims in 2011.
Armstrong sued the USADA last year to stop its investigation of him, arguing it did not have the right to prosecute him. But after a federal judge dismissed the case, Armstrong said he would no longer participate in the investigation.
In October 2012, Armstrong was stripped of his titles and banned from cycling. Weeks later, he stepped down from the board of his foundation, Livestrong.
It is unclear whether Armstrong would face criminal prosecution for perjury should he confess. Armstrong was involved in several cases where he gave sworn testimony that he never used banned drugs.
CNN's Jillian Martin contributed to this report.