KRASNAYA POLYANA, Russia -- A veteran German athlete tested positive for a banned stimulant after Monday's biathlon mass start race, according to the German Olympic Committee.
Evi Sachenbacher-Stehle, an Olympic champion in cross-country skiing who took up biathlon last winter, tested positive for the stimulant methylhexanamine. Both her A and B samples were positive.
She will go home immediately, German officials said Friday.
Methylhexanamine can be found in several supplements, including geranium oil, and the U.S. Anti-Doping Agency has cautioned athletes against accidental ingestion. Multiple athletes in sports like basketball, soccer, and track and field have been slapped with suspensions after accidentally taking the substance.
In a prepared statement provided by the German Ski Association, Sachenbacher-Stehle, who placed fourth in Monday's race, maintained that she had always confirmed the legality of her nutritional supplements with a laboratory.
"I am experiencing the worst nightmare that one could possibly imagine, because I cannot explain how I have received a positive test," she said. "All I can do at this moment is assure everyone that I have at no time deliberately taken banned substances, and I will do everything possible to clear up this matter completely."
Sachenbacher-Stehle is the fourth biathlete to have failed a doping test recently, after the International Biathlon Union in January announced positive tests from a Lithuanian and two Russians.
Stefan Schwarzbach, a spokesman for the German Ski Association, said the association provides its athletes with a list of approved supplements, and said it was possible that Sachenbacher-Stehle had ingested a contaminated product.
"It really seems that it is a mistake," he said. "And she has to handle the consequences."
Under the principle of strict liability, athletes are responsible for banned substances found in their samples regardless of whether they were ingested intentionally or not.
Sachenbacher-Stehle was one of two athletes expelled by their teams Friday for doping.
The Italian Olympic Committee said bobsledder William Frullani failed a doping test in the Olympic Village on Tuesday for the performance-enhancing drug dymethylpentylamine.
The news of Sachenbacher-Stehle's positive test -- bits and pieces of which trickled out Friday -- cast a pall over athletes, coaches, and officials involved in biathlon and cross-country skiing at the Sochi Games.
Many said they were shocked to learn the athlete involved was Sachenbacher-Stehle. Both biathletes and cross-country skiers described her as a cheerful, positive presence on their circuits. American cross-country skier Kikkan Randall called her "the last person, really, that you would suspect."
Some said they found Sachenbacher-Stehle's claims plausible, while others dismissed her denials as typical for an athlete who has been caught red-handed.
"The first line of defense that you always hear, in virtually every possible doping case, is that: 'It was in my supplement. It was inadvertent,'" said Canadian Beckie Scott, a retired Olympic champion cross-country skier who's a member of both the International Olympic Committee, and the executive committee of the World Anti-Doping Agency. "I'm a really hardened cynic when it comes to those kinds of defenses."
American biathlete Tim Burke, whose girlfriend is Andrea Henkel, another member of the German team, said he was "really shocked" to learn of the positive test.
"I'm sure she's taking some sort of supplement that had something in it that wasn't listed on it," Burke said. "I feel awful for her -- she's a multiple-time Olympic champion, and I'm sure she did that clean. And now, she's always going to have this stain on her name."
In 2006, Sachenbacher-Stehle was given a five-day suspension for elevated levels of hemoglobin just before the start of the Turin Olympic Games. Hemoglobin is the protein in blood that carries oxygen, and high levels have been associated with doping--though they can also occur naturally.
On Friday, news reports were quick to cite the incident from 2006, but Burke, the American biathlete, noted that Americans, including Randall and cross-country skier Leif Zimmerman were both handed the same five-day ban.
"And I can guarantee you they weren't doping," Burke said. "Everyone reads that and just sees that as a doping violation. But it's not."