London, Oct. 30 Jamaican star sprinter Usain Bolt has reiterated that his performances are not drug-enhanced.

The 23-year-old, who ran the fastest 100m ever recorded in Berlin back in August - 9.58sec - to win the World Championship, was quoted by The Sun, as saying: "It's going to take a couple of years for people to start believing that you're actually clean." (ANI)