Queensland stewards have confirmed star apprentice Luke Tarrant has tested positive to an illegal drug.

Tarrant was stood down from riding on Christmas Eve after an initial drug test taken at Ipswich early last month returned a positive.

Chief steward Allan Reardon confirmed a second test of the sample had also been found to be positive.

He said full details would not be released until the inquiry which is likely to be next week.

However, it is understood the drug involved is a cocaine derivative.

"The second test confirmed the original," Reardon said.

"In fairness to Mr Tarrant we can say no more."

Tarrant is the third young jockey to return a positive to a drugs test in the past six months.

Matt McGillivray and Ric McMahon were both disqualified for drug offences last year.

Just a year ago, Tarrant celebrated his biggest win aboard Le Chef in the $2 million Magic Millions Classic at the Gold Coast.