Stewards are looking for suitable venue to reconvene an inquiry into a fall at Townsville which resulted in three jockeys being hospitalsed.

In the last race at Townsville on Thursday, Ashley Butler (Jerrazz), Les Tilley (Kanui) and Chelsea Jokic (Sidthekid) fell at the 1000m.

All three were taken to hospital and kept overnight for observation.

Jokic sustained a knee injury, Butler a broken wrist and Tilley a broken nose.

Chief steward Allan Reardon said Townsville stewards had opened an inquiry into the fall and another incident in the race.

"They are hoping to reconvene as soon as they get a suitable date. Tilley lives in Brisbane, Jokic in north Queensland and Butler in central Queensland," Reardon said.

"The Townsville stewards will probably use skype but it will need to a suitable date for everyone."

Stewards have stood down three track workers for testing positive to illicit drugs during no-notice testing at Toowoomba on Saturday.

The track riders tested positive to methyl amphetamine, cocaine and cannabis and have been stood down pending the return of secondary testing.

Queensland Racing Integrity Commission boss Ross Barnett said the commission had adopted an anywhere-anytime approach to drug testing of racing participants.

"This approach is necessary to maintain the integrity of the Queensland racing industry and to ensure the safety of all racing participants and animals," he said.