June 15 (UPI) -- Shelby Houlihan, a former Olympian and American track record holder, says a tainted pork burrito is the reason behind her positive steroid test result and recent four-year ban from competition.
Houlihan wrote a long message about the ban Monday on Instagram. She had received a letter from the Athletics Integrity Unit on Jan. 14, informing her of the disciplinary action.
Houlihan said she provided a drug testing sample Dec. 14 that came back positive for the steroid nandrolone.
The Athletics Integrity Unit released a statement to confirm Houlihan's ban was upheld Tuesday.
"The Court of Arbitration for Sport has upheld the AIU's charge and banned Shelby Houlihan of the USA for four years, starting [Monday], for the presence of a nandrolone metabolite, a violation of World Athletics anti-doping rules," the statement said.
Houlihan said she did not know what nandrolone was when she received the email that first informed her of the positive test.
"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," Houlihan wrote on Instagram. "Pig organ meat has the highest levels of nandrolone."
Houlihan said she compiled a food log to determine what she ate before her 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, Ore.," Houlihan wrote.
Houlihan notified the Athletics Integrity Unit that she believed the burrito was the source of the nandrolone. She said she also took a polygraph test and had her hair sampled by toxicologists in an effort to "prove [her] innocence."
Houlihan said the Court of Arbitration for Sport informed her Friday that it did not "accept" her explanation and upheld the ban.
"I feel completely devastated, lost, broken, angry, confused and betrayed by the very sport that I've loved and poured myself into just to see how good I was," Houlihan wrote.
"I want to be very clear. I have never taken any performance enhancing substances. And that includes that of which I am being accused."
Houlihan, 28, is the American record holder for 1,500-meter and 5,000-meter events. She set the American record in the 1,500-meter race in 2019 at the World Championships in Doha, Qatar. She set the new 5,000-meter record in July in Portland, Ore.
She was to compete in the U.S. Olympic trials from Friday through June 27 in Eugene, Ore. The Top 3 finishers in each event earn a spot in the postponed 2020 Summer Games, which run from July 23 through Aug. 8 in Tokyo.
Houlihan placed 11th in the 5,000-meter race at the 2016 Summer Games in Rio de Janeiro.