British Greco-Roman wrestler Myroslav Dykun, a top medal hope at the London Olympics, has tested positive for amphetamines, British Wrestling confirmed on Thursday.
The 29-year-old, originally from Ukraine, failed a test for the drug and is awaiting the outcome of a B sample.
"I can confirm that he has failed his A sample. The drug was amphetamines," British Wrestling's chief executive Colin Nicholson said.
Dykun won gold in the 2010 Commonwealth Games in New Delhi in the 66kg category and was regarded as one of Britain's best hopes of a medal in the British capital.
He will now miss the Games if his B-test returns positive. He has already been banned from competing and had his funding stopped.
"He is immediately suspended from competition and funding," Nicholson added.
"Under no circumstances do we condone drug-taking in any form -- whether it be recreational or performance-enhancing. British Wrestling will not tolerate such behaviour from anyone
"This is evidence that we are determined to work in partnership to root out anyone mis-using substances."