A man has fallen 30 metres to his death from scaffolding at a building site in the Barangaroo redevelopment in central Sydney.

The death has prompted a union to accuse the Lend Lease construction company of failing to supervise workers properly at the site.

But the company has rejected the accusation as a union attempt to score points off a tragic incident.

Ambulance officers were called to the Hickson Road site at about 8.30am on Thursday but were unable to revive the man, who was pronounced dead at the scene.

Police said he was 30 years old and is believed to have fallen from scaffolding.

Colleagues had administered CPR on the man to no avail and work was halted at the Lend Lease site after the death.

Lend Lease said in a statement: “Our thoughts are with the worker’s family and friends.

“We are investigating the circumstances surrounding the tragic incident.”

Police earlier said the man may have suffered a medical episode before he fell, but that has not been confirmed.

Construction, Forestry, Mining and Energy Union (CFMEU) NSW secretary Brian Parker said Lend Lease did not have a great work safety record.

“We are confident there was a lack of supervision and mentoring for this young bloke,” he said.

CFMEU safety coordinator Michael Preston said it was too early to say exactly what had happened, but the general labourer who died was not trained to work in the area from which he fell.

But in response to the union accusations, Lend Lease said it was “disappointing that anyone would use such a tragic incident to point-score”.

“Lend Lease works tirelessly to eliminate incidents and injuries on its worksites,” the company said.

“Our focus now is on the welfare of the family of the deceased and all of our workers affected by the incident.”

WorkCover NSW inspectors are investigating the death and police will prepare a report for the coroner.