Sportswear giant Adidas has reportedly informed the IAAF that it intends to scrap its sponsorship deal four years before it is due to expire.
The manufacturer, which signed a record £750m kit deal with Manchester United in 2014, is the athletics' world governing body's largest sponsor.
According to BBC Sport, Adidas spoke with IAAF officials last week to reveal that it wants to terminate the contract due to the recent doping allegations that have engulfed the sport.
The IAAF, whose president is Lord Sebastian Coe, has been accused of corruption amid claims that senior officials were aware of widespread doping within Russian athletics.
Neither Adidas nor the IAAF have confirmed the contract termination, but both have released statements claiming that a "reform process" is underway.
