Kamila Valieva's legal team claims her positive doping test was caused by a mix-up with her grandfather's heart medication, the Independent reports.
Over the weekend, Valieva, a 15-year-old Russian figure skater, was cleared to continue competing at the Beijing Winter Olympics due to "exceptional circumstances", despite testing positive for a banned substance.
Traces of trimetazidine, a heart medication, were found in a urine sample taken from the teenager in December, per Reuters.
Now, the teenager's legal team is claiming that she failed the drug test, not because she intentionally ingested the medicine but because her sample was contaminated with the drug.
"Her argument was this contamination happened with a product her grandfather was taking," the International Olympic Committee's (IOC) Denis Oswald told reporters.
"She presented elements which brought some doubts about her guilt, and also she was in a very special situation that the Olympic Games take place every four years, and if she would miss the competition at this Games, the damage could not be repaired," Oswald added.
The court of arbitration for sport (Cas) announced at a hearing in a Beijing hotel on Sunday night that Valieva had been cleared to compete at the Winter Olympics.
It said that banning the young athlete amid her doping case "would cause her irreparable harm".
Matthieu Reeb, secretary-general for Cas, said: "The panel considered that preventing the athlete from competing at the Olympic Games would cause her irreparable harm in these circumstances."
In an interview with Russian broadcaster Channel One, Valieva spoke about how overwhelming the days following the Cas hearing have been.
"These last few days have been very difficult for me," she said. "I'm happy to compete but I’m very tired emotionally."
Valieva, who attended the hours-long hearing via video link, said she felt exhausted after sitting through it all, which ultimately ended in a positive verdict for the youngster.
She added: "I sat there for seven hours, we had one 20-minute break, and I sat there and just watched. It was very difficult but it is apparently one of the moments that I have to go through."