Dreamworld's parent company Ardent Leisure has been charged over the deaths of four people on a theme park ride in 2016.

Ardent Leisure has confirmed that three charges have been filed against it in the Brisbane Magistrates Court under the Work Health and Safety Act.

The charges relate to an alleged failure to comply with health and safety duties, exposing an individual to a risk of death or serious injury.

The maximum penalties for the breaches total $4.5 million.

A coronial inquest into the deaths found many failures at the park, including safety and maintenance systems described as “rudimentary at best” and “frighteningly unsophisticated”.

The four victims died on the Thunder River Rapids Ride when their raft collided with an empty raft and flipped.

Kate Goodchild, her brother Luke Dorsett, his partner Roozbeh 'Roozi' Araghi and 42-year-old Cindy Low were killed.

It was later discovered that a water pump feeding the ride had broken down, causing water levels to drop.

Coroner James McDougall earlier this year said there was a “systemic failure by Dreamworld in relation to all aspects of safety”, and referred Ardent Leisure to the Office of Industrial Relations for a possible breach of workplace laws.

According to Work Health and Safety, Ardent Leisure allegedly failed to ensure “so far as reasonably practicable” the provision and maintenance of safe plant and structures, and safe systems of work.

The company is also alleged to have failed to ensure the “provision of information, training, instruction or supervision that was necessary to protect all persons from risks to their health and safety arising from work carried out as part of the conduct of the business”.

Ardent has issued a statement apologising and defending itself.

“First and foremost, we again express our deepest sympathies to the families and friends of Roozbeh Araghi, Luke Dorsett, Kate Goodchild and Cindy Low for their loss and ongoing suffering and say sorry to all of the people impacted by this tragedy,” the statement says.

“There has been considerable change at Dreamworld over the last few years as was acknowledged by the coroner in his report.

“Dreamworld has taken substantive and proactive steps to improve safety across the entire park and continues to enhance existing systems and practices, as well as adopt new ones, as we develop and implement our safety case in accordance with the Queensland Government's new major amusement park safety regulations.

“The new leadership team is committed to continuing to improve and enhance safety systems and practices with the aim of becoming a global industry leader in theme park safety and operations.”

The charges against Ardent Leisure will be mentioned in the Southport Magistrates Court on July 29.