The highly publicised Barangaroo worksite on Sydney's CBD waterfront has one of the highest rates of injuries, hazards and near misses of any worksite in New South Wales, a freedom of information request has revealed.

Data obtained by the ABC shows workplace incidents have been reported at a level much higher than other building sites of a similar size.

A total of 123 incidents were reported between 2014 and June 2016, approximately five times the rate of other major Sydney projects.

There were just 24 at the Darling Harbour Precinct and 25 on the Sydney Metro rail project over the same period.

The accidents involve fires ignited on the site, workers exposed to live electricity, explosions, and crushed body parts.

In one incident, a high-pressure hose in a generator room dislodged and struck a worker in the face.

In another incident, a steel beam fell through the floor, while in another incident, timber holding together a crane's load fell 16 floors to land near some construction workers.

After millions of dollars and years of construction along one of the last stretches of undeveloped land on the Sydney Harbour foreshore, the stakes for the Barangaroo development are high.

Workers are under-reporting incidents, unions claim

Unions representing workers on the site said the data only tells part of the story.

An electrician formerly employed on the Barangaroo site, Anthony, said not all workers were reporting incidents.

"They're scared. As soon as there's an injury on site and if you go to report it or go to the first aid and they send you away to the medical, you're scared what's going to happen because they try to cover this stuff up," he said.

Anthony said the problem is not isolated to Barangaroo.

"It's happening on various other sites. People falling from a couple of levels, and the boss telling him to take a week off just so they don't have to go through the whole reporting the incident, and the loss of time injury," he said.

Under NSW law, workplace accidents or hazards must be reported directly to the state's construction regulator, SafeWork NSW.

But Electrical Trades Union spokesman Stewart Edward said that was not always happening.

"There's a massive under-reporting of notifiable incidents. We're deeply concerned about the under-reporting," he said.

"It's fairly disturbing when you come across some of the sites where in some cases, you may actually come across maybe a dozen incidents which should have been reported which have never been reported at all.

"But they are very concerned too about the culture of effectively trying to, how would you say, hide the figures in regards to that.

"So we see it as a priority to try and highlight it so that's probably why at Barangaroo the figures look a lot higher because we've spent a fair amount of time on that site to raise those issues."

He said under-reporting has become ingrained in worksite culture.

"There's a culture effectively on sites whereby, really revolves around power," he said.

"Instead of following the law, and sometimes even being advised to follow the law, they will find ways out of not notifying the regulator that something's happened which comes under the definition of a notifiable incident under the Act."

The Barangaroo development, which includes James Packer's $1.5 billion casino and resort, has faced criticism from community groups and advocates who say the project serves private interests with little public benefit.

Stringent safety measures in place at Barangaroo: Lendlease

The ABC's AM asked the site's principal contractor Lendlease for its response to the high rate of incidents -- as well as to claims further workplace accidents are being under-reported.

A former worker at Barangaroo says accidents on the site are under-reported. ( AAP: Dan Himbrechts )

In a statement, a company spokeswoman said safety "is Lendlease's number one priority and we are committed to providing safe conditions for all people in our workplaces".

"We work with all parties including our clients, unions, regulators and workers on safety matters," she said.

Lendlease said: "Stringent safety measures are in place at Barangaroo and incidents including hazards, mechanical breakdown of plant as well as first aid, are reported to our client and SafeWork NSW as required. All incidents undergo thorough investigation of the root cause, underlying factors and corrective actions, to facilitate improvements across the site and on other projects."

Barangaroo is the largest urban worksite in Australia, and, at its peak, had up to 3,000 people working on the site each day.

Work at the site continues, with stage one of the project to be completed later this year.