SUN CITY, South Africa — FIFA is afraid that players at the World Cup could use undetectable stimulants derived from traditional African medicines that aren't currently banned substances.

FIFA medical committee chairman Michel D'Hooghe told The Associated Press on Sunday he wants the World Anti-Doping Agency to analyze some African plants that could give athletes an unfair advantage.

D'Hooghe says he became aware of the extent of the issue at FIFA's medical conference this weekend ahead of the World Cup in South Africa, which starts June 11.

South African team doctor Ntlopi Mogoru says the plants, usually found in tropical African countries like Ghana, can produce steroid byproducts that are not on WADA's list and aren't picked up in doping tests.