A frustrated Dreamworld staffer labelled the repeated failures of a ride’s water pump “ridiculous” about an hour before another malfunction led to the deaths of four guests.

Sarah Cotter was supervising staff on the Thunder River Rapids ride on October 25, 2016 when a water pump failed twice within two hours.

Exasperated by an error she would later tell police happened “frequently” in the days before the tragedy, Ms Cotter sought answers from a park technician who had been called to repair the problem.

“What are we doing about this problem? This is ridiculous,” Ms Cotter told the engineer in a police statement shown to a Queensland Coroner’s Court inquest into the deaths on the Gold Coast on Monday.

Ms Cotter was then told the ride would be shut down if the failure happened again that day.

Approximately an hour later the pump malfunctioned again leading to a collision between two rafts and the deaths of Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi.

Ms Cotter told the inquest she was unaware of a Dreamworld breakdown policy that stated a ride had to be shut down and authority sought from an engineering supervisor if there were two exact malfunctions within a 24-hour period.

“I’ve never heard a thing about the 24 hours,” Ms Cotter said.

Ms Cotter echoed the statements of staff who have already given evidence at the inquest by labelling the 30-year-old Thunder River Rapids ride as one of the most complex to operate in the park.

“It was all manual … it was a very complex panel,” she said.

-AAP