A Dreamworld ride operator says the Thunder River Rapids ride failed to shut down despite him pushing a stop button “two or three times” shortly before a raft flipped and killed four guests.

Peter Nemeth gave evidence on the second day of an inquest into the October 2016 tragedy at the Gold Coast theme park.

Nemeth was at the main control panel of the supposedly family-friendly ride when a water pump failed and the water level in the attraction dropped rapidly, causing a raft to become stranded on rails.

When Nemeth noticed another raft with guests in it on a collision course with the stranded raft he attempted to shut down the ride.

But despite pushing a stop button multiple times, Nemeth said the ride’s conveyor mechanism did not shut down.

“It did not stop even though I pressed it two or three times,” Nemeth said. “It did stop after the rafts had collided.”

By that time Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi had been flung from the raft and fatally injured.

Goodchild’s 12-year-old daughter and Ms Low’s 10-year-old son survived the accident.

Nemeth said he had noticed the water level had dropped moments before the accident when he was loading other guests on to a raft.

He said he knew the pump had malfunctioned as a similar problem had occurred while he was working on the attraction a week earlier.

The inquest at Southport Coroners Court has already heard the “slow-stop” button on the control panel would halt the rafts about eight seconds after the button had been pushed.

Earlier on Tuesday, a forensic crash investigator said his investigation had indicated the button had been pushed after the rafts had already collided.

An emergency stop panel at the nearby unloading dock, which would have stopped the raft conveyor belt in just two seconds, wasn’t pushed at all, the inquest heard.

Senior Constable Steven Cornish said that emergency button could have lessened the likelihood of death, even if it was pushed after the collision.

“It wouldn’t have avoided (the tragedy), it may have limited some injuries. Possibly,” Sen Const Cornish said.

On Monday lead police investigator Detective Sergeant Nicola Brown told the inquest Nemeth panicked during the tragedy and “wasn’t sure at the moment of stress which button to press”.

Nemeth disputed that.

“There’s only one button that stops the conveyor ... I was pushing the red stop button,” he said.

Documents shown in the court showed Nemeth had been trained on multiple occasions to operate the Thunder River Rapids ride.

While some training documents showed the sessions only lasted 15 minutes, James Bell QC, representing Dreamworld’s parent company Ardent Leisure objected that counsel assisting Ken Wallace QC was being misleading in the way he was presenting the training documents.

Nemeth told the inquest the second ride operator, Courtney Williams, had only received training on the attraction on the morning of the tragedy. He also said he’d been told by his supervisor before starting his shift on the Thunder River Rapids ride at 1pm - about an hour before the tragedy - that the attraction pump had already failed twice that day and would have to be shut down for the day if it failed again.

The inquest continues.