Nike said on Friday it plans to shut down its Oregon Project training group after top athletics coach Alberto Salazar was banned for four years for doping.
Salazar, best known for coaching Britain's four-time Olympic champion Mo Farah, was last week handed a four-year suspension by the United States Anti-Doping Agency (Usada) for a catalogue of drugs violations.
The US sportswear giant had initially backed Salazar after the 61-year-old Cuban-born American denied the allegations.
Salazar's doping violations include trafficking in testosterone, tampering with the doping control process, and administering illicit infusions of the fat-burning substance, L-carnitine.
Salazar has vowed to appeal the ban and just last week, Mark Parker, Nike's chief executive, announced that the company was standing behind Salazar, a marathon champion in his 20s and the leading figure in American distance running in the modern era.
But in a memo to staff, Nike CEO Mark Parker said the project was being terminated because of the scandal.
"This situation, along with ongoing unsubstantiated assertions, is a distraction for many of the athletes and is compromising their ability to focus on their training and competition needs," Parker said.
"I have therefore made the decision to wind down the Oregon Project."
Parker said however that Nike would still support Salazar in his appeal against the ban.
"A four-year suspension for someone who acted in good faith is wrong," said Parker in the memo, adding that "the panel found there was no orchestrated doping, no finding that performance enhancing drugs have ever been used on Oregon Project athletes and went out of its way to note Alberto's desire to follow all rules".
However, he admitted that "Alberto can no longer coach while the appeal is pending".
Athletes from the Oregon Project won three gold medals at the World Athletics Championships in Doha that ended on Sunday.
Sifan Hassan of the Netherlands won the women's 1,500 metres and 10,000 while Donavan Brazier of the United States took the men's 800m gold. There is no suggestion either athlete has been involved in doping.
An angry Hassan said she was happy to be tested "every single day" to prove she was a clean athlete.
"I believe in clean sport, I'm always clean, I will always be clean. I believe in the Oregon Project. I've seen Alberto. He's worked really hard and that is what I know," she said in an emotional outburst after running the sixth-fastest time in history to win the 1,500m.
British athlete Farah is also facing new questions about his involvement with Salazar. Farah, who has never tested positive, waited more than two years after the accusations were first made against Salazar before parting ways with the coach in October 2017.
Farah will run in the Chicago marathon on Sunday, with Galen Rupp, another NOP athlete, also taking part.
Nike's decision to shut down the project came after athletes including US runner Kara Goucher, who was coached by Salazar from 2004 to 2011 and provided key evidence in the case against him, told the BBC Nike could not justify keeping it open.
"It (NOP) has to go," Goucher said.
"If I was Nike I'd be bringing in some new coaches and move on from this Oregon Project, because clearly it had principles not in line with clean sport and we have to just start over."
Jeffrey Brown, a Texas endocrinologist who treated many of Salazar's athletes at the Oregon training hub in Portland, was also suspended for four years.
Nike's share price has been hit by the Salazar scandal but following Friday's announcement, it was up 0.55 percent at $93.51 in pre-market trade in New York.
The US company has $4.5 billion in annual running-related sales, according to Bloomberg data, and it is the biggest sponsor of running around the world.