The control panel of a Dreamworld ride which malfunctioned and led to the deaths of four people was confusing for operators, an inquest has heard.
A Dreamworld staff member claimed she'd been told not to "worry about" an emergency stop button for the ride on which four guests died in October 2016.
An inquest into the tragedy at the Gold Coast theme park began on Monday, with the Southport Coroners Court hearing staff were confused by the ride's controls.
Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi died instantly after being flipped from a raft when the Thunder River Rapids ride malfunctioned.
Barrister Steven Whybrow, representing victims Kate Goodchild and Luke Dorsett, said an emergency stop button was not clearly labelled and a staff member was unaware of its exact function.
"She was told not to worry about that button, no-one uses it?" Mr Whybrow asked lead police investigator Detective Sergeant Nicola Brown.
"Yes," Det Sgt Brown replied.
Mr Whybrow added that a memo sent to staff in the days before the tragedy had dissuaded staff from using the emergency button.
The inquest heard the main control panel for the ride also did not have an emergency switch which would shut down the ride, with a second switch needing to be used to halt the ride's conveyor belt.
"It is a confusing control panel, and that has been raised by the auditors," Det Sgt Brown said.
The inquest heard the ride operator at the control panel when the tragedy occurred "wasn't sure which button to press" under the stress.
Det Sgt Brown said an automatic sensor to shut down the ride if water levels dropped to a dangerous level would have prevented the tragedy.
"We're talking about human beings ... it was a human being that has to stop it," she said.
The inquest continues.