With the Badminton World Federation now officially naming Datuk Lee Chong Wei as the Malaysian shuttler who failed the drugs test at the World Championships in Copenhagen, the spotlight is now on whether the banned substance found in his system, Dexamethasone, is a performance-enhancing drug. A medical doctor helps shed some light on Dexamethasone, why it's banned in sports, and the time it takes to be flushed out of the body.

This is a report by Audrey Raj.