Powell handed 18 month ban.Reuters

Former world 100m record holder Asafa Powell has been banned for 18 months for doping offences.

Powell, 32, tested positive for banned substance oxilofrine in June 2013 at Jamaica's national trials and has been suspended from competition since the case was disclosed last July.

A disciplinary panel of the Jamaica Anti-Doping Commission announced on Thursday that the 31-year-old sprinter will be excluded from competition until December 2014, with the ban backdated to the time of his original sample collection in June 2013.

He is permitted to return on December 20.

Earlier this week, Powell's former teammate Sherone Simpson was handed an identical ban for an similar offence.

Two time silver medallist Simpson has persistently protested her innocence, claiming she had not intentionally taken the banned stimulant and plans to appeal.

"We feel that this ruling is incredibly unjust and we will be appealing to the Court of Arbitration for Sport immediately," a statement from Simpson's agent Paul Doyle read.

Powell has pleaded a similar case, insisting he had unwittingly taken the supplement in a supplement given by his coach.

Both Powell and Simpson will now miss the Commonwealth Games taking place in Glasgow this July.

Jamiacan discus thrower Allison Randall was also handed a two-year ban for using the prohibited substance on Tuesday.

Randall, Simpson and Powell with three of the five Jamaican athletes to test positive for banned substances in national championships last year.