Gender tests on the South African athlete Caster Semenya are yet to be completed.
The 18-year-old had been expected to find out this week if she was eligible to compete as a woman.
But the IAAF says it will not discuss the case at its meeting in Monaco this week.
Semenya won the 800m at the World Championships in Berlin in August, only for her achievement to be overshadowed by the gender test revelations.
Depending on the test results, she could be suspended, told to have surgery or cleared to run as a woman.