A member of the Czech Republic's sprint kayak K4 crew for the London Olympics has been banned six months for doping by the International Canoe Federation.
Jan Sterba tested positive for a banned stimulant during Olympic qualifying in Poznan, Poland on May 17.
The Czech Canoe Federation announced the ban on Wednesday, but said Sterba is appealing the verdict and still hopes to compete at the London Games.
Sterba acknowledged he used a food supplement called "Shot Gun" that contains the substance beta-methylphenylethylamine.
Sprint kayak events in London are scheduled for Aug. 6-11.