Apprentice Jamie Quinnell has been suspended after testing positive to a banned substance.

A sample was taken from Quinnell after he rode at the Warwick Farm meeting on October 5 and the rider pleaded guilty to a breach of AR 81A at a Racing NSW stewards' hearing on Friday.

He will be permitted to fulfil his riding engagements at Randwick on Saturday.

Following that, Quinnell's apprentice permit will be suspended until January 1 next year which means he will not be permitted to ride trackwork or in barrier trials until that date.

Quinnell's licence to ride in races will be suspended until June 8.

However, that ban will be reduced to April 8 if he completes a satisfactory period of professional counselling.

Racing NSW stewards took into account factors such as Quinnell's good record, his forthright evidence and the fact he had already commenced professional counselling.