USA's 1500m and 5000m star Shelby Houlihan says she has been given a four-year ban after testing positive for the steroid nandrolone, claiming it was from a burrito she ate.
Although the suspension has not been confirmed by anti-doping authorities, she confirmed the news ahead of USA's Olympic team trials for the upcoming Tokyo Games.
Houlihan, 28, claims she had never even heard of the steroid and puts it down to a burrito she ate.
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"I want to be very clear. I have never taken any performance enhancing substances," she wrote on Instagram.
"I have since learned that it has long been understood by WADA (World Anti-Doping Agency) that eating pork can lead to a false positive for nandrolone, since certain types of pigs produce it naturally in high amounts. Pig organ meat has the highest levels of nandrolone.
"In the following five days after being notified, I put together a food log of everything that I consumed the week of that December 15 test.
We concluded that the most likely explanation was a burrito purchased and consumed approximately 10 hours before that drug test from an authentic Mexican food truck that serves pig offal near my house in Beaverton, Oregon. I notified the AIU (Athletics Integrity Unit) that I believed this was the source.
"I did everything I could to prove my innocence. I passed a polygraph test. I had my hair sampled by one of the world’s foremost toxicologists.
"WADA agreed that test proved that there was no build up of this substance in my body, which there would have been if I were taking it regularly."
Her coach Jerry Schumacher said: "What we are witnessing here is a great tragedy in the history of American distance running.
"Not only is Shelby an exceptionally talented athlete, but she has also developed her talent through hard work and discipline. She is as tough as nails. She is an exceptional team-mate.
She loves to compete. She just might be the best 1500m runner in the world this year but we will never get the opportunity to find out and that is a tragedy.
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