Adidas is ending its sponsorship deal with athletics' world governing body in the wake of the doping scandal, according to reports.
The sportswear giant has told the International Association of Athletics Federation (IAAF) it is terminating its contract four years early, the BBC said.
The move comes after a damning report by the World Anti-Doping Agency (Wada) said the London 2012 Olympic Games was "sabotaged" by "state-sponsored" Russian doping.
Sources told the BBC that the decision will result in tens of millions of dollars in lost income to the IAAF, which is led by Lord Coe.
An Adidas spokeswoman refused to comment on whether the company was ending its deal as the IAAF's biggest sponsor.
But she said: "As you know, A didas has a clear anti-doping policy in place. Therefore, we are in close contact with the IAAF to learn more about their reform process."
An IAAF spokesman told the BBC: "The IAAF is in close contact with all its sponsors and partners as we embark on our reform process."
Adidas is also the oldest commercial partner of world football's governing body, Fifa, which is embroiled in its own corruption scandal.
Former Olympic champion Lord Coe was elected president of the IAAF in August last year. He has faced mounting calls to explain how much he knew about doping and corruption after previously serving as vice president since 2007.
Earlier this month, Wada's chairman, Dick Pound, delivered a second report which revealed "corruption was embedded" within the IAAF under former president Lamine Diack.
It is understood Adidas believes the doping revelations in that report constitute a breach of its agreement with the IAAF, according to the BBC.
The 11-year sponsorship deal with the IAAF - reportedly worth around £23 million - was signed in 2008 and was due to run until 2019.