Sebastian Coe has hit out at Nestle and said the IAAF "will not accept" the food giant's move to terminate its sponsorship of world athletics' governing body.
Swiss-based Nestle said on Wednesday it was concerned its own reputation could be damaged by association, owing to the doping and corruption scandals involving the IAAF, and would be seeking to end its financial backing with immediate effect.
Nestle is a financial backer of the IAAF Kids' Athletics programme, being its main sponsor since agreeing a five-year deal that took effect in January 2012 and is entering its last year.
It is understood to have been paying around one million dollars [£690,000] per year but has asked the IAAF to remove all Nestle branding from its website as part of its withdrawal.
The IAAF said the programme is due to benefit three million children in 2016, but needs the sponsorship funding.
IAAF president Coe vowed to fight the move, saying in a short statement: "Angered and dismayed by today's kids' athletics announcement. We will not accept it. It's the kids who will suffer."
Nestle's move came as a new setback to the governing body and Coe, who was elected last August and has since seen the reputation of the IAAF suffer repeated blows.
"We believe this could negatively impact our reputation and image and will therefore terminate our existing agreement with the IAAF." - Nestle statement
The IAAF was understood to be preparing a legal challenge, with Coe not alone in being furious.
Nestle said in a statement: "We have decided to end our partnership with the IAAF Kids' Athletics programme with immediate effect. This decision was taken in light of negative publicity associated with allegations of corruption and doping in sport made against the IAAF.
"We believe this could negatively impact our reputation and image and will therefore terminate our existing agreement with the IAAF, established in 2012.
"We have informed the IAAF of our decision and await a formal acknowledgement from them that our partnership has ended."
The IAAF first responded to Nestle's announcement by saying it was in touch with the food giant.
It said in a statement: "The IAAF is in discussion with Nestle concerning the final year of its five-year partnership with IAAF Kids' Athletics."
Coe's involvement indicates how protective the IAAF is of its programme. When announcing the tie-up with Nestle in 2012, the IAAF said the funding would go towards courses for lecturers and coaches, with a view to supporting the training of large numbers of children, encouraging healthier lifestyles.
On Wednesday the IAAF said its programme had involved 15 million children aged from seven to 12 years old. It said that Kids' Athletics, with Nestle's funding, planned to reach 15 more countries in 2016, training 360 lecturers and 8,640 physical education teachers, with three million children to be involved.
That is now under threat, as the IAAF battles to cling to its blue-chip sponsor. Last month it emerged that German sportswear giant adidas was looking to end its deal as a leading sponsor of the IAAF four years early.
Athletics is reeling from two damning reports by the World Anti-Doping Agency's [WADA] independent commission which revealed "state-sponsored" doping in Russia and raised questions about widespread doping in other countries.
Life bans for blackmailing athletes and covering up positive drugs tests were last month handed to Papa Massata Diack, who is the son of former IAAF president Lamine Diack and was a marketing consultant for the organisation, together with former Russian athletics federation [ARAF] president and IAAF treasurer Valentin Balakhnichev, and Alexei Melnikov, a senior ARAF coach.
All three have appealed against the sanctions to the Court of Arbitration for Sport. The IAAF's ethics commission found the trio had blackmailed Russian Liliya Shobukhova, the London marathon winner in 2010, and made her pay a bribe for a positive drugs test to be covered up.