Semenya took gold after a powerful run in Berlin's Olympic Stadium
The South African Olympic Committee (SAOC) has cast doubt on controversial world 800m champion Caster Semenya's proposed return to competition.
Earlier this week, world athletics' governing body the IAAF said she was free to run despite its ongoing investigation into her gender.
But SAOC president Gideon Sam said the 19-year-old was not eligible to run until the IAAF rules on her status.
He added: "The matter over the results of her test are sitting with the IAAF."
Semenya stormed to gold in the World Championships in August 2008 but hours before she was due to compete it emerged the IAAF had demanded that the South African should take a gender test before the event amid fears she was not eligible to compete as a woman.
Semenya has not competed since Berlin but it is believed she wants to run in a series of domestic races in South Africa.
Before news came through from SAOC that she could not run, her coach, Michael Seme, had told BBC Sport that she was in training but needed to race against local opposition before a return to international events.
Athletics South Africa had also confirmed her comeback, but refused to discuss dates, saying they wanted to keep her out of the media spotlight.
Semenya was 18 when she won the world 800m title. Her time of one minute, 55.45 seconds was 2.45 seconds quicker than Kenya's defending champion Janeth Jepkosgei, who finished second, with Britain's Jenny Meadows taking bronze.
The IAAF has never officially suspended Semenya following her victory in Germany but says its investigations are ongoing.
In November, the South African sports ministry said Semenya would be able to keep her 800m gold medal.