The Victorian branch of one of Australia's most militant unions has been placed into administration following serious allegations of criminal conduct by senior officials on major construction sites, including government projects.

It comes after CFMEU boss John Setka stepped down from his role on Friday ahead of the publication of the criminal allegations.

The union became infamous during Melbourne's harsh Covid lockdowns, turning on its own members by calling them 'far-right Nazis' after failing to stand up for them against vaccine mandates.

In remarkable scenes, thousands of construction workers rallied outside the CFMEU office in Melbourne, demanding to see Setka in a wild confrontation.

National Secretary Zach Smith made the announcement on Monday after an emergency meeting of the national executive.

“The CFMEU has zero tolerance for criminality and anyone found to have engaged in criminal conduct while representing the CFMEU will be identified and removed,” stated Smith. He stressed the union's primary goal: "The CFMEU has one purpose and one purpose only and that is to defend and advance the safety and conditions of workers."

Smith bizarrely condemned general 'smearing' of officials and delegates due to their histories or personal relationships.

“Cancel culture will never be our culture,” he claimed.

“There are corporates and right-wing politicians who want our union to go away... they just don’t believe blue collar workers deserve decent pay or proper safety standards on site.”

Prime Minister Anthony Albanese however supported the decision, calling it a “good thing” and condemning the alleged links to organised crime.

“It is an indictment of the leadership of the CFMEU that they haven’t been held to account,” he told ABC radio. Expressing disdain for John Setka, Albanese declared, “He has no legitimate role in the union movement.”

Albanese stressed the need for further action, including possible deregistration and a halt on accepting donations from the Victorian branch.

“We will take whatever action is appropriate... where there are breaches of the law, such as people offering bribes, those people need to be prosecuted,” he said. “People who are working on construction sites around Australia are hardworking Australians. They shouldn’t be tainted.”