The Jamaica Anti-Doping Commission (JADCO) will be step up its education and testing programmes following five athletes, including Olympic medallists Asafa Powell and Sherone Simpson, testing positive for banned substances, the country's Prime Minister said.

Portia Simpson-Miller, who is also the country's Minister for Sports, added the country's anti-doping body had uncovered 15 positive tests from 860 samples in the past four years.

Powell and Simpson said on Sunday they had tested positive for stimulant Oxilofrine (methylsynephrine) at the Jamaican national championships last month.

Discus thrower Allison Randall said on Monday she had also tested positive at the championships.

All have denied knowingly taken banned substances.

"We (JADCO) intend to ramp up the public education programme in the high schools and commence the sensitization programmes at the primary school level," Simpson-Miller said in Jamaica's Parliament on Tuesday.

"We need to initiate a system for high school level testing for athletes involved in training and competition in sport, in accordance with appropriate approvals from the Ministry of Education, ISSA (Inter-econdary School Sports Association) and the parents and guardians of these youngsters."

Simpson-Miller said JADCO had notified the five athletes of their positive tests in writing last week.

One, a junior athlete, is yet to confirm the notification of the doping violation.

She said all five had until July 19 to indicate whether they want their 'B' sample tested, though one had already said they would like the second sample analysed.

Powell and Simpson's agent Paul Doyle told Reuters earlier this week his two clients would ask for their 'B' samples to be tested.

JADCO could also ask for the 'B' sample to be analysed, Simpson-Miller added.