Russian figure skater Kamila Valieva claimed she tested positive for a banned substance due to a "mix-up with her grandfather's heart medication," an Olympic official said Tuesday.
Driving the news: International Olympic Committee permanent chair Denis Oswald said during a news conference the 15-year-old's defense to the Court of Arbitration for Sport (CAS) before it ruled she could continue to compete at the Beijing Winter Games "was this contamination happened with a product her grandfather was taking."