MARK RALSTON/Getty Images

Nadezhda Sergeeva has become the second Russian athlete to fail a drugs test at the 2018 Winter Olympics, with the bobsled pilot testing positive for a banned heart medication.

Per the Associated Press (h/t Patrick Reevell of ABC News) on Friday, Sergeeva has denied taking the substance. She finished 15th in the women's bobsleigh event alongside Anastasia Kocherzhova.

In early February, Sergeeva made headlines for wearing a shirt saying "I Don't Do Doping" in a promotional video, as ABC's Muhammad Lila shows:

Scandal continues to surround Russian participants after curler Alexander Krushelnitckii failed a drugs test, forcing him and his partner and wife, Anastasia Bryzgalova, to hand back the bronze medal they achieved in Pyeongchang, South Korea.

Russian Bobsled Federation president Alexander Zubkov told the Associated Press the bobsled pilot had passed a drugs test five days before, and team doctors confirmed they hadn't prescribed the substance to Sergeeva.

"Federation representatives at the Olympics are starting to prepare a defense," said Zubkov.

Per Reevell, a Russian Bobsled Federation statement read, "The Federation and the athlete herself understand the measure of our responsibility and how what has happened can affect the fates of all the teams."

The latest setback further damages Russia's attempts to win favour with the International Olympic Committee after being denied entry to Pyeongchang 2018 due to state-sponsored doping in the lead-up to and during the 2014 Winter Games in Sochi.