Track riders Ben Saunders and Wade Clasohm remain in intensive care after suffering spinal injuries in a fall at Toowoomba.
Saunders and Clasohm were riding trackwork early on Saturday morning when their mounts crashed to the ground.
Trackwork was closed at Toowoomba for more than an hour while ambulance men attended to the pair.
They were initially taken to the Toowoomba General Hospital but then transferred to the Princess Alexandra Hospital in Brisbane on Sunday.
A spokesperson for the Princess Alexandra Hospital said both remained in the intensive care unit and were ventilated and sedated but in a stable condition.
The spokesperson said she could not comment further on their conditions.
However, it is understood both will require surgery.
The Queensland Racing Integrity Commission is expected to open a full inquiry into the fall after some initial inquiries were made on Monday.
Chairman of Toowoomba stewards Rion Hitchener said he was unable to comment further on the incident until all the evidence was available.
WorkCover Queensland will also open an inquiry into the incident
Injured apprentice Melanie Bolwell is being kept sedated in the Gold Coast hospital after a three-horse fall at Warialda in north-west NSW on Saturday which claimed the life of senior rider Darren Jones.
Bolwell suffered bleeding on her brain with doctors monitoring her situation before any decision on surgery.
Leanne Henry also came down in the fall and suffered concussion and a broken collarbone.
She is expected to be out of action for six weeks.
— Isobel Roe (@isobelroe) April 10, 2017