Over the past few days there’s been a swirl of reports about allegations that the Russians used doping methods to improve athlete performance at the Sochi Winter Olympics in 2014.

The story was first reported in the New York Times by Rebecca Ruiz and Michael Schwirtz.

The report claims that the program was state-run and that dozens of athletes participated. At least 15 of the participants were medal winners. The report’s source is a former anti-doping official.

Allegedly, the urine sample bottles supplied by the athletes were tampered with and the athletes’ own urine was replaced with clean urine as part of the scheme.

You can read an even longer account in Slate.