Paris - The organizers of the Tour de France said Thursday they would not allow 2005 world road race champion Tom Boonen to take part in this year's race because he tested positive for cocaine.

"Tom Boonen's image and behaviour are incompatible with the image of the Tour de France," the Amaury Sports Orgainzation said in a statement issued in Paris.

The 28-year-old Boonen, a Belgian who rides for the Quick Step team, is considered one of the strongest sprinters in the world. In April of this year he tested positive for cocaine for the second time in one year in an out-of-competition doping test.

The doping test was administered two weeks after Boonen won the prestigious Paris-Roubaix one-day road race for the third time.

Cocaine is not considered a performance-enhancing drug by cycling authorities and suspension is not automatic after a positive test. But Boonen was also barred from the Tour de France last year after he tested positive for cocaine.(dpa)