By Nick Butler at the Main Press Centre in Sochi

Evi Sachenbacher-Stehle is one of two athletes to have been confirmed as failing a drugs test this evening ©AFP/Getty ImagesFebruary 21 - Germany's double Olympic gold medal winning biathlete Evi Sachenbacher-Stehle and Italian bobsleigher William Frullani have each been sent home after recording the first two positive doping cases of Sochi 2014.

The news comes as a bitter double-blow after a Games that until today had been notable for the lack of positive drugs results.

Both athletes have tested positive for dimethylamylamine, which is also known as methylhexanamine, and both are blaming contaminated food supplements for the results.

Following the announcement earlier today that an unnamed member of the German had recorded an "abnormal" result, it was reported in Germany and on insidethegames that the athlete was Sachenbacher-Stehle and this was confirmed by the German Olympic Sports Confederation (DOSB) this evening.

The 33-year-old from Traunstein, winner of gold medals at Salt Lake City 2002 and Vancouver 2010 in cross country skiing, previously served a five-day "health" suspension at the beginning of the 2006 Games due to a high haemoglobin level.

Sachenbacher-Stehl, who had switched to biathlon from cross country two years ago, has been expelled from the German team and will be sent home as soon as possible.

Former decathlete William Frullani has also been sent home after a positive test ©Getty ImagesFormer decathlete William Frullani has also been sent home after a positive test
©Getty Images

Frullani meanwhile is a former decathlete who was due to compete for Italy in the four-man bobsleigh competition which begins tomorrow.

In a statement this evening, Italy's governing body CONI says it was informed by the International Olympic Committee that Frullani tested positive in a test taken in the Olympic Village on February 18.

CONI says Frullani asked his B sample to be analysed and that it "confirmed the positive result, resulting in his exclusion from the Italian delegation."

He will be replaced in the four-man bobsled team by Samuele Romanini.

Frullani is blaming the positive test on a contaminated food supplement and reportedly told Italian officials that he had brought the product from a website based in the United States.

Sachenbacher-Stehle meanwhile, said through her management that she was experiencing the "worst nightmare you can imagine" because she "cannot at all explain how the positive test has come about."

She claimed that she had all her supplements checked before the Games and there was nothing illegal in any of them, before adding: "I can only expressly assure everyone concerned that I at no time consciously took forbidden substances and I will be doing everything to have this cleared up completely."

Biathlete Irina Starych was removed from the Russian team after her positive test was confirmed two weeks before the Games ©AFPGetty ImagesIn the biggest case in the build-up to the Games, another biathlete in Irina Starych was removed from the Russian team after her positive test was confirmed two weeks before the Games ©AFPGetty Images

This news is a bitter blow to both teams - with the Germans currently fourth in the medals table with eight gold, four silver and four bronze medals after leading earlier in the week - while Italy lie 22nd with two silver and six bronze medals. 

Until now, no other athletes are known to have failed tests during the Games, although Russian biathlete Irina Starykh was withdrawn from her country's team two weeks beforehand after testing positive.

But, speaking last November, Germany's IOC President Thomas Bach warned countries that a positive drugs test would overshadow the achievement of any team at Sochi 2014.

The anti-doping programme at Sochi 2014 is the  toughest for any Olympics with 57 per cent more tests than at Vancouver 2010.