Former 100m world record holder Asafa Powell was banned for 18 months by a Jamaican anti-doping disciplinary panel after he tested positive for a banned substance last year.
The Jamaican sprinter, 31, tested positive for the stimulant oxilophrine at last year's national championships and the ban has been backdated to June 21 2013 - the day he provided the sample. His ban will end on December 20.
I want to reiterate that I have never knowingly taken any banned substances
Powell said he would lodge an appeal against the decision.
"This ruling is not only unfair, it is patently unjust," he said in a statement.
"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. Unfortunately, this was not the case.
"This is the first time in nearly 12 years of being in the sport and over 150 tests that I have had an adverse finding. It is for a stimulant, a stimulant that is only banned during competition and experts have declared has no performance enhancing effects.
Powell's sanction comes two days after his former training partner Sherone Simpson received an 18-month suspension from the same panel for the same substance. Another Jamaican, Olympic discus thrower Allison Randall, was also handed a two-year ban for using the prohibited diuretic hydrochlorothiazide on Tuesday.
IAAF spokesman Chris Turner declined to comment on Powell's punishment, saying only: "This is a legal process following IAAF rules which are in accordance with those of WADA (the World Anti-Doping Agency), and the IAAF does not comment until cases are closed."
Turner added that 'the case concerns an international athlete and the full, reasoned decision of the member federation has to be sent to the IAAF and considered by the doping review board'.