Five Jamaican athletes involved in a doping affair can compete at the world championships because a Jamaican doping panel has postponed its hearing until after the event finishes on Sunday night.
The Internattonal Athletics Federation's general secretary Pierre Weiss says it's entirely in Jamaica's hands whether the athletes compete in the 4x100 and 4x400 metres relays,
He says if Jamaica wins medals and the athletes are subsequently banned the IAAF will be forced to take away their medals.
Sprinters Yohan Blake, Marvin Anderson and Sheri-Ann Brooks as well as Allodin Fothergill and Lansford Spence had tested positive for the stimulant methylxanthine.
The Jamaican Anti-Doping Commission's disciplinary committee cleared them initially then the commission appealed the committee's verdict.
It said the substance had a similar structure to tuaminoheptane, a banned stimulant according to the World Anti-Doping Agency.