All 44 athletes on the Jamaican team, including sprint superstar Usain Bolt, have been drug tested at their training camp in Russia ahead of the world athletics champs.
Agents from the World Anti-Doping Agency arrived at the camp in Moscow, where all of the athletes had blood samples taken.
It's not know known if an entire national team has been asked before to undergo testing on the eve of a major competition previously.
The Jamaican track and field program has been under increased scrutiny over the past two months after former world 100 metres record holder Asafa Powell and his training partner Sherone Simpson were among five athletes who tested positive at the Jamaican championships in Kingston in June.
