South African sprinter Simon Magakwe has been handed a two-year suspension after failing to provide a urine sample late last year.
Magakwe, who holds the South African 100m record, refused to submit an out-of-competition test on December 22, according to Athletics SA president Aleck Skhosana.
The 28-year-old represented his country at last year's Commonwealth Games in Glasgow, where he reached the 100m semi-finals before finishing in seventh spot.
He had been in contention to feature at the World Championships in Beijing later this year.