Queensland stewards have warned trainers run high risks if they use unlicensed staff following several cases around the state.

In one a strapper returned a positive test to cannabis during a random inspection of stables at Innisfail, in north Queensland, and it was discovered he was also unlicensed.

The strapper was suspended for two months and stewards warned handling a horse while under the influence of drugs or alcohol could void insurance.

Queensland Racing Integrity Commissioner Ross Barnett reminded all trainers and their staff they needed to be licensed.

"The Racing Integrity Act requires the Commission to have licensing standards for each racing code to reinforce the integrity of racing activities, the safety of participants involved in training or racing licensed animals and their welfare," Barnett said.

"There have been some recent incidents where people have been found working in stables for example without appropriate licences."

"We don't want to penalise people with fines but the Commission has a duty to ensure the integrity of the racing industry."