The crisis engulfing one of Australia'sAustralia's biggest unions - the CFMEU - has deepened in the wake of damning allegations that underworld figures and senior bikies were parachuted into lucrative union roles and infiltrating taxpayer-funded construction jobs.

But the Victorian Premier and the PM have been accused of turning a blind eye, with claims they failed to act on allegations of extreme violence and standover tactics sent to them, in 2022.

On Monday,  the CFMEU placed its Victorian branch into administration.

The national secretary, Zach Smith, defending his former boss, in light of this CCTV footage, which shows John Setka visiting the home of a fellow union official to dump a suitcase, scrawled with the word ""dog"".

But corruption and criminality began long before Sekta's reign.

The Builders Labourers Federation - the CFMEU's predecessor - was deregistered in the wake of scandals involving corruption, thuggery and violence in 1986.

Now, history could be repeated, as the federal government threatens regulation again.