The alleged assault of two government investigators at Sydney's Barangaroo development site proves the construction watchdog must be restored, Employment Minister Eric Abetz says.

Senator Abetz said the attack by union officials on the Fair Work Building and Construction officers was a cause for great alarm and showed the industry had returned to the “bad old days of lawlessness”.

News Corp on Monday reported that a male officer had been shoulder charged by a union official while investigating workplace breaches last week.

A female officer was also verbally assaulted by one official, who called her a “f***ing s**t” as she entered the site, News Corp says.

The allegations have been referred to NSW Police.

Senator Abetz said the incidents highlighted the need to restore the Howard government-era Australian Building and Construction Commission (ABCC) – a move that has so far been blocked by Labor and the Greens in the Senate.

The body was established by the coalition but abolished by the Labor government led by Julia Gillard.

“Labor’s … foolish abolition of the ABCC has seen a return of the worst forms of bullying and thuggery in the building industry,” Senator Abetz said in a statement.

“A re-established ABCC would work to ensure that the laws of the land are enforced on building and construction sites.”