Sumgong was handed a four-year ban by Kenya's anti-doping agency after it proved she used the banned blood-booster.
She was the first Kenyan woman to bag gold in the Olympic marathon title during the Rio Olympic Games in 2016.
But on Friday in a statement, the IAAF Disciplinary Tribunal said claims that she was injected with EPO by an 'imposter' were false.
The Tribunal banned the Kenyan distance runner starting January 17, 2019, for another four years.
“We welcome the decision of the Disciplinary Tribunal. We hope that it sends a message to dopers that the AIU has strong investigative capabilities and does not tolerate false evidence in doping cases," the head of athletic unit said.
Brett Clothier with the support of ADAK, said they will be able to pursue the case.
"They are a valuable partner in the fight against doping in Kenya,” she added.
Under Article 13(2) of the World Anti-Doping Code, she has 21 days to appeal the decision. This means that any appeal must be filed with the Court of Arbitration for Sport (CAS).
In 2017, the Olympic marathon champion apologised to Kenyans after testing positive for erythropoietin.
"I’m sorry to all my family and my team. Four years I'll be back," Sumgong said via her Twitter account.
ADAK officials said Sumgong failed an out of competition test in April, days before she was due to defend her London Marathon title.
Her four-year ban has been backdated to April 3.
This is the date on which she was provisionally suspended by the International Association of Athletics Federations (IAAF).
-The Star