Adidas has told the IAAF that it is to end its sponsorship agreement with athletics' governing body four years early, according to reports.
Adidas signed an 11-year agreement with the IAAF in 2008 but, according to a report from the BBC, has now signalled its intentions to end the deal.
The IAAF has been engulfed in a doping scandal over the last year, with a World Anti-Doping Agency independent commission reporting of "state sponsored" doping in Russia, while a second commission report said "the IAAF Council could not have been unaware of the extent of doping in athletics and the non-enforcement of applicable anti-doping rules."
If the reports are confirmed, they will serve a huge blow to IAAF president Lord Coe, who succeeded Lamine Diack in the role in August last year.
There has been no comment from the IAAF or Adidas.