An unnamed jockey has failed a drugs test at the Mount Isa Mailman Express races on Thursday.
The Queensland Racing Integrity Commission Integrity Investigations Team were at the meet to conduct testing.
Racing Integrity Commissioner Ross Barnett said the team performed stable inspections and human and animal testing at Mount Isa's first TAB meet in four years.
"The Integrity Investigations Team conducted 13 stable inspections in Mount Isa resulting in one stewards' direction relating to the disposal of medications and four racing participants were educated regarding appropriate treatment book keeping and recording," Mr Barnett said.
"While the IIT reported trainers at the Mount Isa meeting were operating with a satisfactory level of compliance, a drug testing operation resulted in the standing down of one senior rider pending the outcome of secondary testing and a stewards' inquiry."
Mr Barnett said the jockey would not be named until the matter is determined.
"The Commission continues to work with the racing industry to provide confidence for the betting public in the integrity of race meetings throughout the State," he said.
It was an action-packed meet on Thursday with former Magic Millions Classic winner Le Chef winning the opening race.
Then in Race 2 favourite Alik ($1.55) bit the dust in unusual circumstances.
Alik's blinkers came loose forcing jockey Ric McMahon to take the horse wide.
Alik finished runner-up, beaten half a length by Rock Tsar ($7.50).
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