The verdict clearing Nigerian hurdler Tobi Amusan of a breach for skipping drug testing was challenged by the Athletics Integrity Unit (AIU).
According to the anti-doping authorities, an appeal was sent to the Court of Arbitration for Sport late last week.
Amusan was temporarily banned because she had missed three examinations in a year.
The penalty was eventually lifted by an appeals body, allowing the Nigerian to take part in the global championships earlier this summer, when she placed sixth.
The 26-year-old might receive a year or more of suspension if proven guilty.
Last weekend, Amusan won the Diamond League championship for the third year in a row.