France's international midfielder Zinedine Zidane says he took creatine when he was playing for Juventus but stopped using the performance-enhancing supplement when he joined Real Madrid.
"I used to take creatine when I was playing for Juventus but it's not illegal," he told the French daily Le Monde. "In Madrid we don't use dietary supplements, just vitamins".
Creatine is not on the IOC's list of banned substances but its sale is banned in France and its use is banned by several sports federations.
Tennis player Mary Pierce, winner of the 2000 French open, is one of the few French sports stars who admitted using creatine.
But a former national rugby coach was quoted as saying creatine-taking was a "reality" of the French rugby championship.