Racing Queensland stewards hope to open inquiries next week involving five trainers whose horses have been confirmed to have had cobalt levels above the accepted level.

Chief steward Alan Reardon has been handed control of the cobalt inquiries after RQ's integrity officer Wade Birch was stood down pending an unrelated investigation into greyhound racing.

Reardon said every effort would be made to hold the inquiries as soon as possible.

"The trainers are entitled to prepare their case and we want to be fair as possible," he said.

"If we can start next week we will but it is not set in concrete."

RQ named three harness racing and two thoroughbred trainers who have horses which returned cobalt samples above the legislated threshold.

The gallops trainers are James McConachy and Len Treloar.

Harness racing trainers Shawn Grimsey and Trevor Lambourn both had two horses return samples above the threshold while Ken Belford had one sample.