Stellenbosch - Top South African sprinter and former African 100m champion Simon Magakwe has been banned two years for refusing to undergo an out-of-competition doping test.
Magakwe did not submit to a test when asked to do so by anti-doping officials at his South African training base on December 22 last year, Athletics South Africa president Aleck Skhosana has said on Wednesday.
Skhosana said that he had been notified by the International Association of Athletics Federations that Magakwe's window to appeal has now expired and he has been banned until December 22, 2016.
"The rules must be observed.
"The rules are international," Skhosana said.
"Simon is a senior athlete who has been around for many years."
The 28-year-old Magakwe is the South African 100m record holder and the only South African to run the 100 under 10 seconds.
He ran 9.98 at last year's national championships.
Magakwe's ban was announced days before he was to defend his title at this weekend's nationals in Stellenbosch.
Magakwe, the 2012 African champion, will miss this year's world championships in Beijing and the 2016 Olympics in Rio de Janeiro.
The test he refused to take was an IAAF-ordered test because of his world ranking, the South African Institute for Drug-Free Sport said.
Magakwe appeared at an IAAF disciplinary hearing earlier this year, South Africa's anti-doping body said.