Alex Schwazer has been excluded from the London Olympics after he tested positive for a banned substance.
As a result, the Italian will not defend to 50km walking title that he won during the Beijing Games four years ago.
The 27-year-old has since admitted the offence and has confirmed that he will not be lodging an appeal.
Schwazer is now expected to call time on his career, which took off when he won a bronze medal at the 2005 World Championships.
