KINGSTON (AFP) - Jamaican sprinter Asafa Powell, the former 100m world record holder, slammed the 18-month doping ban meted out to him on Thursday calling it "unfair" and "unjust".

"This ruling is not only unfair, it is patently unjust. Panels such as these, I understood, were assembled to allow athletes who, consciously or unconsciously come into conflict with the rules of sport, a chance at equitable redemption," Powell said in a statement posted on his website.

"Unfortunately, this was not the case." Powell's lawyer had already vowed to appeal the decision handed down by a three-member panel of the Jamaica Anti-Doping Commission Disciplinary Panel, which unanimously ruled that Powell, who blamed his positive result for a banned stimulant on a nutritional supplement, was negligent.

Panel chairman Lennox Gayle announced the suspension, which is due to end on December 20 of this year.