Andrew Demetriou has reopened the debate over the legality of the anti-obesity drug AOD-9604, claiming there is a ''classification issue'' about the supplement believed to have been administered to Essendon's players last year.

In its February report, the Australian Crime Commission says of the AOD-9604 peptide: ''During phase two clinical trials it was also found to have an anabolic effect to cartilage tissue and may promote cartilage creation and repair and have a capacity to enhance muscle formation.'' But it then adds: ''AOD-9604 is not currently a WADA prohibited substance.''

AFL CEO Andrew Demetriou. Credit:Getty Images

However, later in the report, it says, ''AOD-9604 is not currently prohibited under category S2 of the WADA prohibited list. AOD-9604 is not approved for human use.''

The drug is not banned under section S.2 because its performance-enhancing benefits are in question.