Barangaroo bomb threat revealed as hoax

Construction is back underway at Sydney's Barangaroo site after a bomb threat was found to be a hoax - again.

NSW Police received the bomb threat via a triple-0 call on Friday morning.

About 1700 workers were pulled off the waterfront site as police sniffer dogs scoured the area.

The threat was found to be a hoax by Friday afternoon and workers returned to the site.

It is the second time in just over a week the construction project has been evacuated due to a bomb threat.

There was a similar threat that brought works to a grinding halt in June.

CFMEU NSW secretary Brian Parker said each bomb threat was a setback for the site.

"You've got companies down there told when they will move in and take up residency," he said.

"This is putting that back further and further with the disruptions."

A basement fire and subsequent re-ignition in March also caused construction delays.