The CFMEU administrator sent two teams of investigators away, despite their expertise in integrity and corruption cases.
These teams were assembled to uncover graft in the union but were swiftly disbanded, leaving serious misconduct allegations unaddressed for months.
One source said the administrator was concerned that seeking more powers from the federal government 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, but the investigation was ultimately abandoned.
The Albanese government's CFMEU reform chief, Mark Irving KC, has been criticized for his handling of the situation, including failing to enact advice to seek more powers to deal with wrongdoing.
Author's summary: Corruption investigation at CFMEU abandoned despite serious allegations.