A signed statutory declaration, provided by a union whistleblower who assisted Mr Parker after he allegedly obtained the leaked information, states it was used to help formulate an industrial campaign against a company that had been fighting the CFMEU in legal cases in several states. "State secretary Brian Parker told me that he had a contact in CBUS who could discreetly ... leak him the information he asked for," the statutory declaration says. "A short time after this, he came to my office and gave me a printed copy of the information he said was supplied to him. He said to me to keep this document secret and not tell anybody else." It has been confirmed the database was used by the NSW CFMEU to call the private phone numbers of South Australian, Queensland and NSW employees of construction company Lis-Con. The NSW CFMEU branch allegedly received the information from CBUS after senior union leaders met in Sydney last year to discuss ways to attack Lis-Con. Relations between the company and the union became extremely hostile when the company's management lodged defamation writs against the CFMEU in Queensland and Western Australia. The union whistleblower said: “They were a company the union wanted to squash. The leaked information was intended to put enough pressure on them so the word would get out that they were not a company contractors should use.”

The construction workers were quizzed about their entitlements to get them to put pressure on the company's management. In a small number of cases, the workers allegedly were falsely told the call was being made on behalf of CBUS. Sources close to the workers said the unsolicited contact had deeply unsettled them and some suspected CBUS had leaked their details, which "shocked and upset" them. A Lis-Con spokesperson said the company would refer the allegations to the Australian Federal Police and the Australian Privacy Commissioner. Mr Parker has issued a statement denying any knowledge of the allegedly leaked database or how it arrived at the CFMEU. The huge alleged privacy breach will spark debate about unions’ control of industry funds and raise serious questions for Mr Parker’s fellow union officials on the CBUS board. The CBUS board is chaired by former Victorian premier Steve Bracks. Also on the board are Australian Council of Trade Unions president Ged Kearney, CFMEU national secretary Dave Noonan and NSW CFMEU president Rita Mallia, who works closely with Mr Parker and is now obliged as a fund director to act on the alleged leak to the CFMEU.

There is no suggestion the CBUS board knew of the leaking of the members’ details and a CBUS spokesman says the allegations will be the subject of an internal investigation. "The sole purpose of the disclosure of any personal information [of workers] ... is to ensure the payment of fund members’ superannuation entitlements," the spokesman said. "Any disclosure made or used for purposes other than this would be of serious concern to CBUS. "The fund has only recently become aware of the specific allegations raised. They are currently subject to investigation and review at a number of levels, including being subject to internal investigation." It is understood at least 80 per cent of Lis-Con’s workers whose details were leaked from CBUS are not members of the CFMEU. Furthermore, it is understood most Lis-Con employees who had their details leaked worked outside of NSW. None consented to having their personal information provided to the union.

The whistleblower said he decided to confirm the alleged leak involving Mr Parker because he believed inappropriate conduct at the NSW CFMEU had gone unchecked by the union. The revelations put intense pressure on Mr Parker and come after he and his union faced allegations earlier this year about its ties to alleged corrupt building company owner and organised crime figure, George Alex. The CFMEU's national office is already investigating allegations Mr Parker covered up a death threat made by another senior union official to a CFMEU staff member who had spoken out about the NSW branch’s support of Mr Alex’s allegedly corrupt operations. The revelations of the alleged CBUS leak is likely to fuel concerns already held by senior federal government ministers and industry figures about the union movement’s control of industry super funds, including CBUS. It is the 11th biggest fund in Australia, manages more than $20 billion and represents almost 700,000 members. Last year, the CFMEU’s Victorian boss John Setka revealed he and other CFMEU bosses were considering telling their members to pull billions of dollars in funds from CBUS because of the fund's financial ties to building company Grocon, which has waged a fierce industrial war with the CFMEU.

A senior building industry executive said it was widely suspected that CBUS’ close ties to the union had led to several cases of inappropriate information sharing between the fund and the union, which is only entitled to limited information from CBUS to check on workers’ entitlements. The information allegedly leaked to Mr Parker contains personal details that cannot be shared under Australian law.