The bribery is alleged to have involved large-scale money laundering, Fairfax Media reported.
The raids are also linked to Chinese firms that are thought to be employing foreign workers on poor pay and conditions.
According to sources from NSW Police and the construction industry, the raids uncovered evidence that the companies were involved in the facilitation of bribery, as well as paying Chinese plasterers off the books to avoid paying tax and workers’ entitlements.
An industry source told Fairfax that a Construction, Forestry, Mining and Energy Union (CFMEU) organiser is under police investigation for allegedly accepting a bribe by plastering companies involved in the scheme with a large Sydney firm.
The plastering companies are reportedly involved in multimillion dollar developments in Sydney, and use non-unionised labour.
The Australian Federal Police (AFP) told Fairfax Media NSW that the organisation was working with the union royal commission taskforce to conduct the raids, and had “executed search warrants in the Sydney suburbs of Guildford and Belmore on 2 December”.
“Police seized a number of documents and two people are continuing to assist with enquiries,” the AFP explained.
“As this matter relates to an ongoing investigation, no further details can be provided at this time.”
On Sunday, Dave Noonan, national secretary of the CFMEU’s construction division, said that the organiser under investigation denied the allegations.
“The union has had no contact from the [trade union royal commission] taskforce in relation to this matter,” he said.
Federal Police are reported to have raided properties last week as part of an investigation into a construction official who is suspected of being bribed by businesses.