Fans urged Caster Semenya not to quit athletics after she posted a cryptic tweet following the loss of her appeal against regulations restricting testosterone levels in female runners.
Semenya will have to take medication to reduce her testosterone level if she is to continue competing at 800m.
The Olympic champion, 28, is confirmed for that distance in the Diamond League season opener in Doha on Friday.
Semenya's tweet included a quote which referred to knowing when to walk away.
One person replied to Semenya's tweet saying "never give up" while another urged her to "fight until the end".
But Semenya posted another tweet shortly afterwards that read: "That's me and will always be. I'm finished."
However, Athletics South Africa president Aleck Skhosana appeared to play down suggestions Semenya could quit by describing her as "an outstanding athlete who has a continuous hunger for great results".
Skhosana added: "We believe that Caster will shake off the world attention currently around her to give us another exceptional performance and give the world new topics to talk about."
Always tell someone how you feel because opportunities are lost in the blink of an eye but regret can last a lifetime.