The counsel assisting the coroner at the inquest into the Dreamworld ride tragedy has slammed a legal firm for "compromising" evidence by publicly announcing three key witnesses were planning to sue the Gold Coast theme park.

Key points: Shine Lawyers announced outside inquest three witnesses would be suing Dreamworld

Shine Lawyers announced outside inquest three witnesses would be suing Dreamworld Ken Fleming QC says Shine's announcement was opportunistic and compromised inquest

Ken Fleming QC says Shine's announcement was opportunistic and compromised inquest Shine Lawyers stands by comments and rejects suggestion witnesses knew nothing of the move

The inquest in the Southport Magistrates Court is investigating the deaths of four people who died when a raft on their Dreamworld ride tipped over, and will hear from three safety officers and an engineer, who are planning to sue Dreamworld for psychological damage.

Shine Lawyers made the announcement in Brisbane on Tuesday, claiming their clients "cannot unsee" the horrific scene at the Thunder River Rapids Ride in October 2016.

Ken Fleming QC, who is leading the inquest as counsel assisting, said the Shine announcement was opportunistic and done without the knowledge of the witnesses themselves, or their lawyers involved in the inquest.

"Obviously they [Shine Lawyers] are using the opportunity build their own profile," he told the ABC.

"I was very disappointed because it compromises their evidence.

"It makes it look as though they're giving evidence at the inquest for the purposes of the common law procedure and that, of course, just isn't the case."

Former Dreamworld safety officer John Clark is one of the three planning to sue. ( AAP Image: Dave Hunt )

Lawyers representing the families of Cindy Low, Kate Goodchild, Luke Dorsett and Roozi Araghi will question witnesses and theme park management over the course of the inquest, which Mr Fleming said was already running behind schedule.

Safety officers John Clark and Shane Green gave evidence in the District Court at Southport on Wednesday, while another safety officer Rebecca Ramsey and engineer Paul Burke are yet to appear.

Mr Fleming, who is also the Northern Territory's Independent Commissioner Against Corruption, said the inquest must be kept separate to any outside legal action from witnesses.

"They're here to give evidence in respect of the inquest — the inquest being an investigative, non-adversarial process."

Queensland Emergency Service personnel at the Thunder River Rapids ride. ( AAP: Dan Peled )

Mr Fleming said some witnesses being represented by Shine Lawyers did not know the announcement was to be made on Tuesday and the lawyers acting for the witnesses in the inquest were also taken by surprise.

However, a spokeswoman for Shine Lawyers rejected that criticism.

"We sought permission from the clients involved in the inquest to speak on their behalf before offering comment," she said.

"Our comments sought to highlight the ordeal that our clients have endured and continue to suffer through as first responders at this horrific scene."

The spokeswoman stood by the firm's comments.

"As a law firm, we take access to justice very seriously — particularly where personal injury and the mental health of our clients is affected," she said.

"Every person who suffers injury in the workplace is entitled to representation and support of the law."

One of the former safety officers, paramedic John Clarke, told the inquest on Wednesday that while he was in the water trying to resuscitate one of the victims, the water receded further and another victim was revealed.

His colleague Shane Green told the court even the best surgeons in the world could not have helped the four victims on that day in October 2016.

The inquest will continue this morning.