Doping samples from Russian long jumper Darya Klishina are suspected by a World Anti-Doping Agency (WADA) investigator and athletics governing body IAAF to have been manipulated, a German report said Sunday.
"RUS athlete Klishina: alleged #doping cover up according to McLaren Report/IAAF: two DNA from different persons in one urine sample at more than one of Klishina's urine sample bottles scratches allegedly have been found (sic). Suspicion of manipulation," ARD journalist Hajo Seppelt tweeted.
Seppelt uncovered doping practices in Russia in a documentary in 2014 which led to a first WADA probe and the suspension of the Russian athletics federation.
United States-based Klishina was originally the only Russian track and field athlete allowed to compete in Rio.
But on Saturday the IAAF said it had withdrawn her "special eligibility based on new information received," a decision that applies not only for the Olympics but all other competition.
Klishina has been was informed about the measure and is going to the Court of Arbitration for Sport in a bid to overturn the ruling and get into the Rio competition which has qualifying Tuesday and the final Wednesday.
The CAS said Saturday a decision was expected late Sunday.
Klishina was originally allowed to compete in Rio as her US residency meant she had undergone independent doping tests outside of Russia.
However, she has been implicated in a subsequent WADA report by Richard McLaren which investigated allegations of state-sponsored doping in Russia and the manipulation of samples.