Rigger Tim Macpherson from Newcastle had been working at the at the Barangaroo Ferry Hub worksite for at least six months.
The Maritime Union of Australia spokesman Paul Keating said he attempted to inspect the site in November 2016. At the time, he was notified about concerns that the barge being used did not comply with maritime standards.
"At the time I came down with another official to speak with the workers to have a look at the barge to assess if it was up to maritime standard and to make sure that the operation was safe," he said.
"I was met with opposition from the contractor, McConnell Dowell, in accessing the site, after which I contacted Roads and Maritime Services to find out whether the vessel was up to standard.
"These companies refuse our right on entry even when we raise these issues of safety with them."
McConnell Dowell's Australian managing director, Jim Frith, said in a statement that the company's thoughts were with the man's family.
"We are providing his employer with all the assistance they need to support his family, and all affected staff are being offered support and counselling,'' the statement said.
"The full circumstances are unknown at this time and McConnell Dowell will continue to work with the authorities as they investigate the incident."
Moreover, the Construction, Forestry, Mining and Energy Union's (CFMEU) state secretary Brian Parker said the Australian Building and Construction Commission (ABCC), was making work sites more dangerous by preventing unions from visiting them.
However, Minister for Employment Michaelia Cash
said the CFMEU was dishonest to claim any link between the ABCC and yesterday's workplace death.
"The ABCC is not a safety regulator and it is highly dishonest for the CFMEU to claim that it is in any way related to this matter," she said in a statement.
"It is utterly disgraceful that any union would seek to politicise a workplace death, particularly given the incident occurred less than 24 hours ago."
Prime Minister Malcolm Turnbull also rejected claims government changes are to blame for MacPherson’s death and sent his condolences to his family.
“Every industrial accident is a tragedy and our condolences go, our sympathies go to the family,” said Turnbull.
SafeWork NSW is investigating the accident.
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A 32-year-old man has died after a heavy metal beam fell on his torso and crushed him while he was working on a barge at Sydney’s Darling Harbour.