Jamaican sprinter Asafa Powell has issued a statement calling his 18-month ban for taking a banned substance 'patently unjust'.
Powell, 31, said he had unknowingly taken oxilofrine when he was using a legal supplement called Epiphany D1.
He added that his team had contacted doping authorities to point out that oxilofrine was not listed as an ingredient for Epiphany D1.
The former world record holder also questioned the severity of his punishment, claiming it was "clearly not based on the offense nor the facts surrounding it".
Powell's team is now preparing to take his case to the Court of Arbitration for Sport in Switzerland.