American judo fighter Nick Delpopolo was expelled from the Olympic Games on Monday after testing positive for marijuana he said he ate accidentally before arriving in London.
Delpopolo is the first of the 10,500 games athletes to fail an in-competition doping test.
His case is the fifth positive test for a banned substance reported by the IOC since their official London Games testing period began in mid-July. The other four athletes were caught before competing.
"My positive test was caused by my inadvertent consumption of food that I did not realize had been baked with marijuana, before I left for the Olympic Games"
Judo fighter Nick Delpopolo
The International Olympic Committee said it disqualified Delpopolo from the men's 73-kilogram class, where he placed seventh.
Delpopolo tested positive for metabolites of cannabis after competing on July 30.
He apologized to the United States team in a statement acknowledging he was 'embarrassed by this mistake.'
"My positive test was caused by my inadvertent consumption of food that I did not realize had been baked with marijuana, before I left for the Olympic Games,'' Delpopolo said in a statement released by the U.S. Olympic Committee.
"I look forward to representing my country in the future, and will rededicate myself to being the best judo athlete that I can be,'' he said.
Delpopolo "shall have his Olympic identity and accreditation card canceled and withdrawn immediately,'' the IOC said.
Defending Olympic 50K race walk champion Alex Schwazer was caught doping in Italy and will miss the London Games.
The Italian Olympic Committee, also known as CONI, said on Monday that Schwazer tested positive for doping and has been removed from the team.
CONI President Gianni Petrucci said Schwazer had admitted to doping on what was a 'bitter day' for Italian sports.
Earlier on Monday, the team said an unidentified athlete had failed a doping test conducted for the World Anti-Doping Agency before arriving in London.
Details of the offense were not given.
The 27-year-old Schwazer had been due to defend his 2008 Olympic title in the 50-kilometer walk on Sunday. Schwazer won gold at the Beijing Games in an Olympic record time of 3 hours, 37 minutes, 9 seconds.
His doping confession on Monday meant 'one less medal but more cleaning' house, Petrucci told Italian state television.
The Italian athletics federation said it was notified of Schwazer's doping test results on Monday afternoon.