The CFMEU administrator sent corruption investigators away and later had to sack a top figure.
Two teams of investigators with experience in integrity were assembled to uncover corruption in the union but were swiftly disbanded.
A confidential source confirmed that CFMEU administrator Mark Irving KC failed to enact advice to seek more powers from the federal government to deal with wrongdoing.
One source said Irving was concerned that seeking more powers could risk reviving calls for the coalition's Australian Building and Construction Commission.
Former AFP officer Chris Craner was recruited to help investigate wrongdoing at the CFMEU.
The Albanese government's CFMEU reform chief abruptly abandoned the anti-corruption teams, leaving serious misconduct allegations untouched for months.
Author's summary: CFMEU corruption investigation teams were dismissed.