After the New York Times and German broadcaster ARD uncovered the positive drug tests of 23 Chinese swimmers before the 2021 Olympics in Tokyo, the country is firing back. A spokesperson for its foreign ministry said Monday that “The relevant reports are fake news and not factual.”

China has held that the athletes were accidentally exposed to small levels of trimetazidine, a substance banned because it can help blood flow and reduce recovery time. It’s the same drug that disrupted the figure skating world until a January ruling banned the Russian skater Kamila Valieva and redistributed the medals. Both China and Russia said their athletes unknowingly injected the heart medication through contaminated food. The Court of Arbitration for Sport ultimately rejected Valieva’s excuse—that some of her grandfather’s medication ended up in her strawberry dessert—and banned her for four years.

The World Anti-Doping Agency has stood by its decision to not punish the Chinese swimmers or publicize the initial case, saying strict COVID-19 restrictions in China made it difficult to investigate the cases and China’s explanation.