Disgraced U.S. Olympian Nick Delpopolo -- I Didn't Mean to Eat Those Weed Brownies

U.S. judo fighter Nick Delpopolo says he had NO IDEA the baked goods he consumed before the Olympics contained weed. Really, he swears.

Nick was booted from the 2012 Games after failing a drug test ... and now he says he has a perfectly good explanation -- he was tricked into eating pot.

The 23-year-old just released a statement saying his dirty test was "caused by my inadvertent consumption of food that I did not realize had been baked with marijuana."

The International Olympic Committee draws a hard line when it comes to drugs ... they expelled Delpopolo from the games, stripped him of his accreditation, and will change the standings in his event. He had placed 7th in the competition.

In a statement released by the USOC, Delpopolo says, "I apologize to U.S. Olympic Committee, to my teammates, and to my fans, and I am embarrassed by this mistake."