KINGSTON, Jamaica (AP) -- Jamaican discus thrower Allison Randall has acknowledged that she is one of five Jamaican athletes who tested positive for a banned substance at the national championships last month.

Randall holds the island's record for discus and competed at the London Olympics. Her statement says she was "shocked and surprised" at the findings. She hopes her backup sample will clear her name.

Two of Jamaica's marquee sprinters, Asafa Powell and Sherone Simpson, tested positive for the stimulant oxilofrine at the same meet. They say they didn't knowingly break any rules.

The Jamaica Athletics Administrative Association issued a brief statement Monday saying an anti-doping management process has started for the athletes. It did not identify the two other athletes who tested positive.

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