KEY POINTS:
Troy Harris faces charges after returning a positive test to a prohibited substance when jockeys were tested for drug and alcohol at Matamata races last Saturday.
Harris was one of 10 jockeys tested at Matamata.
He was stood down from his rides at Te Rapa yesterday after being met on arrival on course by racecourse inspector Bryan McKenzie.
"It wasn't possible to do it beforehand because we were not advised until mid-morning," said McKenzie.
Troy Harris was engaged for Izonit in Saturday's $2.2 million Telecom Derby at Ellerslie.
Izonit's co-trainer Wayne Hillis said a replacement was still to be confirmed.
"It's left us up in the air. We've had a few offers to ride the horse, but I need to talk to the owners."
Last Saturday Harris rode Te Akau Rose to win the $125,000 Duke Of Bedford Matamata Breeders Stakes.
At the victory presentation Te Akau manager David Ellis and trainer Mark Walker made a public plea for Harris to upgrade his dedication. Harris completed his apprenticeship with Mark Walker last year.
McKenzie said a date for the hearing would probably be known by the weekend.
