Kingston (Jamaica), April 10 (IANS/CMC): Olympic 100m silver medallist Sherone Simpson plans to appeal an 18-month suspension for a drug test she failed last year.

An independent disciplinary panel suspended Simpson until Dec 20, 2014 after she tested positive for the stimulant Oxilofrine at the Jamaican National Championships last June, reports CMC.

The three-man panel unanimously agreed that the athlete had been grossly negligent in all circumstances and was being punished accordingly.

But Simpson’s agent, Paul Doyle, has dismissed the ruling as unfair.

"We are disappointed at the ruling. We think it is unjust and we will be appealing," Doyle said.

He said an appeal would be filed immediately.

The ban will run from June 21, 2013 to Dec 20, 2014, which means Simpson will miss all of the 2014 season including the inaugural World Relay Championships in May and the Commonwealth Games in late July.

"We are happy that the period of ineligibility started from the sample collection period," Simpson's attorney Kwame Gordon said.

"So she would have served most of her sanction already, but we will have to get instructions from her going forward."