Jamaican sprinter Sherone Simpson has been handed an 18-month ban for testing positive for a banned stimulant.

The former Olympic relay champion was handed the suspension, backdated to June 21, 2013, by a disciplinary panel of the Jamaica Anti-Doping Commission on Tuesday.

The 29-year-old tested positive for oxilofrine at the Jamaican trials last year.

The ban means she will be ineligible to compete until December 20 this year. Her agent Paul Doyle confirmed the suspension to Press Association Sport, branding it "unjust" and saying Simpson would appeal.

The ban would rule Simpson out of the Commonwealth Games in Glasgow in July. The commission ruled she had been "negligent in all the circumstances", it was reported.

Simpson, who also has two Olympic silver medals, has always protested her innocence, claiming she did not intentionally take the banned stimulant.

She has blamed the positive test on a supplement provided by her Canadian trainer Chris Xuereb, who has claimed he was being made a scapegoat.

Simpson's compatriot and training partner Asafa Powell, the former 100m world record holder, also tested positive for the same substance at the Jamaican trials.

The highly-anticipated ruling on his case is expected on Thursday.