Nike has confirmed it has ended its sponsorship of cycling star Lance Armstrong due to "insurmountable evidence" that he was a drug cheat, the company said.
The US sports giant said in a statement on its website that it was terminating its contract with the cyclist "due to the seemingly insurmountable evidence that Lance Armstrong participated in doping and misled Nike for more than a decade".
"It is with great sadness that we have terminated our contract," the company said.
Anheuser-Busch followed Nike’s announcement by saying it would not renew its relationship with Armstrong at the end of 2012
Both Nike and the brewing giant said they would continue to support the Livestrong charity.
Nike also said it will take his name off the Lance Armstrong Fitness Centre at its world headquarters, the LA Times reported. RadioShack also acknowledged it had ended a sponsorship deal it signed with Armstrong in July 2009, but declined to disclose when the decision was made, the newspaper said.
Armstrong could lose at least $US50 million over the next five years, Forbes reports.
Nike's announcement came within minutes of Armstrong announcing he was stepping down as the chairman of Livestrong, the charity he founded for people affected by cancer, saying the scandal surrounding him was distracting from its mission.
"To spare the foundation any negative effects as a result of controversy surrounding my cycling career, I will conclude my chairmanship," Armstrong said in a statement posted on the Livestrong website.
Dropped ... Nike has severed its ties with Lance Armstrong. Photo: AP
Nike's severing of ties followed allegations published in the US press that had embroiled the company directly in Armstrong's doping scandal.
Kathy LeMond, the wife of US cyclist Greg LeMond, reaffirmed to the New York Daily News testimony she first made in 2006 that a mechanic from Armstrong's USPS cycling team told her he believed Nike had paid $500,000 to an international cycling official to cover up a 1999 positive drug test.
Nike issued a short statement on Tuesday night US time denying Mrs LeMond's allegations: "In response to the offensive allegations in today's New York Daily News, Nike vehemently denies that it paid the former International Cycling Union president, Hein Verbruggen, $500,000 to cover up a positive drug test," the statement read. "Nike does not condone the use of illegal performance enhancing drugs."
The announcements came a week after the US Anti-Doping Agency (USADA) released a report of more than 1000 pages detailing accusations of widespread doping by Armstrong and his teams when he won the Tour de France seven consecutive times from 1999 to 2005.
The report's purpose was to show why USADA banned him from cycling for life in August and ordered 14 years of his career results erased - including those Tour titles.
The International Cycling Union (UCI) faces growing pressure to reveal how the 41-year-old American was able to escape detection for so long.
Although fingers have pointed at Armstrong for years, the UCI, cycling's governing body, has never sanctioned him and it has since been suggested that some officials looked the other way.
UCI is considering the sanctions imposed by USADA. Rejecting them would likely set up a fight with USADA in the Court of Arbitration for Sport.
Legal experts have said the sheer and unprecedented volume and detail of the USADA allegations could lead US prosecutors and companies to consider fresh criminal and civil actions against Armstrong.
"Lance Armstrong stepping down as chairman of the foundation and Nike dumping him were inevitable once the report came out last week," Ashley McCown, president of Solomon McCown, a Boston-based public relations firms specialising in crisis communications, said.
"The findings in the report were too damning to ignore. Lance Armstrong is a brand unto himself. And Nike as a premiere brand cannot afford to have its image tarnished.
"Lance is damaged goods and he should not expect any corporate sponsor to come knocking at his door any time soon."
Nike has a history of staying with embattled sports stars, having continued to sponsor golf star Tiger Woods after his infamous sex scandal.
The firm also renewed ties with American football star Michael Vick after his prison stay for his role in a dogfight gambling ring.
But Vick and Woods were able to resume their sports careers, an option the USADA ban has closed for Armstrong.
His recent attempts to compete in world-class triathlons are also out, although he can compete at lesser events as he did earlier this month.
Armstrong's Livestrong exit came two days before he was due to speak at a 15th anniversary gala for the charity in his hometown of Austin, Texas. Livestrong has raised nearly $US500 million since 1997.
"It has been a great privilege to help grow it from a dream into an organisation that today has served 2.5 million people and helped spur a cultural shift in how the world views cancer survivors," Armstrong said.
Contributions have actually risen this year as the USADA probe gathered momentum. For the year 2012 to date, the foundation has reported revenue of $US33.8 million, up 2.1 per cent from this point a year ago, according to documents provided to Reuters.
Since late August, when Armstrong said he would not contest the USADA findings and the agency said it planned to strip him of his titles, Livestrong has received more than 16,000 contributions, averaging about $US97 each.
Livestrong's iconic yellow wristband was launched in 2004 in collaboration with Nike. More than 80 million Livestrong wristbands have been sold, donations that were in part inspired by Armstrong's now-tainted cancer comeback.
Armstrong has always maintained he did not take banned substances, but said he would not fight the USADA charges after losing a US federal court case challenging the group's appeals process and jurisdiction.
"The evidence shows beyond any doubt that the US Postal Service Pro Cycling Team ran the most sophisticated, professionalised and successful doping program that sport has ever seen," USADA chief executive Travis T Tygart said.