KINGSTON, Jamaica (AP) — Jamaican Olympic discus thrower Allison Randall has been banned from the sport until June 2015.

Tuesday's ruling by Jamaica's Anti-Doping Commission comes after Randall tested positive for a banned substance at June's national championships. The three-member panel said it could not establish how the substance came to be in her body.

Randall had testified earlier that she believed the source was a supplement she was taking called "Animal Pak." She appeared via Skype during Tuesday's hearing but showed no reaction after the ruling.

Randall had represented Jamaica during the 2012 Olympics.

The commission also is expected to issue a much-anticipated ruling on Tuesday in the case of Olympic sprinter Sherone Simpson. She tested positive for the stimulant oxilofrone and has blamed her new trainer for providing her with supplements.