MONCHENGLADBACH, Sept 16: IOC President Jacques Rogge said on Saturday authorities were making progress in the fight against doping in sport but conceded it was impossible to catch all the cheats.

“I think we are making progress because as you have seen a lot of very famous athletes have been caught and that proves exactly that the system is working,” Rogge said on the sidelines of the hockey World Cup.

“We are very humble in our fight against doping,” he added.

“We are not pretending that we can catch all the cheats but we catch many cheats and I think this is a very strong deterrent.”

Rogge's comments come after a number of sports had been rocked by high-profile doping cases in recent months. Marketing experts have warned the adverse publicity could affect the amount of cash flowing into sport.

US cyclist Floyd Landis tested positive for the male sex hormone testosterone on his way to victory in this year's Tour de France and Olympic 100 metres champion Justin Gatlin faces a life ban after a positive test for the same drug.

“The fight against doping will always be a very difficult one because cheating is embedded in human nature,” he said.—Reuters