An inquiry into high cobalt levels returned by two horses in Queensland trainer Rochelle Smith's stable has been adjourned.

The hearing which opened in Toowoomba on Thursday heard the Smith-trained Grey Countess and Vimzig had returned cobalt levels well above the national threshold of 200mcg per litre of urine.

Grey Countess had an elevated level when she ran second at the Gold Coast on May 30 and Vimzig's level was also above the limit when he won in Toowoomba on May 16.

After initial evidence was taken Smith asked for an adjournment so she could seek legal advise.

She has not been charged and stewards have granted her request for the adjournment.

Central Queensland trainer Jamie McConachy has been granted a stay on the 18 months disqualification he received on Tuesday.

McConachy has been banned for a cobalt irregularity found in Vandalised after he won the 2014 Rockhampton Cup.

McConachy's lawyer Matt Tutt said his client had appealed and the stay would be in place until the hearing.