Construction sector insiders say the absence of legal protections and the fear of career ramifications mean they cannot afford to come forward and speak to the construction union's administrator.

The Construction, Forestry and Maritime Employees Union's (CFMEU) construction and general division was forced into administration in August after the Nine Network aired allegations the division had been infiltrated by underworld and bikie figures and was rife with intimidation and bullying.

The Fair Work Commission appointed Mark Irving KC as CFMEU administrator to investigate the union's activities and ensure it operates in the interest of members.

As part of that process a call was issued for people to report their experiences, with an anonymous reporting mechanism established.

But insiders have said that fear, coupled with the absence of whistleblower protections for contractors wanting to disclose their experiences with the CFMEU, has left them feeling they cannot risk sharing their experiences in detail.

The federal government has conceded that additional protections may be necessary to combat the "reluctance" some workers have about coming forward.

Having previously been targeted by the CFMEU, one long-time construction sector insider — who has asked to remain anonymous for safety reasons — said there was no way they would come forward to the administrator because doing so would put them right back in the union branch's sights.

The insider, who has worked on major Victorian infrastructure jobs, said the union had the power to destroy any possibility of earning an income.

"They break you or you succumb," the Victorian contractor said.

"They shut you down indefinitely until you play the game.

"There seems to be no consequence to their action that is strong enough to slow them down."

'A total gap'

CFMEU members disclosing allegations of wrongdoing by the construction union to the regulator are eligible for whistleblower protections. Contractors are also covered when blowing the whistle on wrongdoing within a company they are working with but those protections do not extend to allegations against a union. Experts say those protections are weaker than those afforded to companies.

Griffith University law and public policy expert and Transparency International Australia chair AJ Brown said there was a "total gap" in protections for contractors in this situation.

"If in fact the wrongdoing relates to the behaviour of the union and union officials and members, then they don't get the protection that a union member would get, nor would they be protected under the corporations act in the same way that an employee would," he said.

"It's just a really good example of why people are sceptical about the strength of whistleblower protections when there are so many technicalities being caused by the fact there are multiple regimes with so many inconsistencies.

Employment and Workplace Relations Minister Murray Watt said the government was open to making changes to legislation and regulations to encourage more people to share their experiences with the administrator.

"I am concerned about the ongoing reluctance on the part of complainants to come forward, and we are considering what further steps can be taken to address this," Senator Watt said.

He said changes to extend protections under the Fair Work Act might need to be expanded further.

"The reality is that some of those protections only apply to certain groups — particularly employees of a union, officials of a union," he said.

"So, it may be that we need to extend that to provide those protections to a broader range of people."

Professor Brown said several current reviews into whistleblower protections offered the government an opportunity to put in place consistent rules so people could be confident to come forward.

"When it comes to the union, the information from union members, employers and contractors is absolutely vital," he said.

A spokesperson for administrator Mark Irving said the administration process extended additional protections.

"The administration's complaints platform provides whistleblower protections in line with the legislation and the policies of the administration extends confidentiality beyond those covered by the act," the spokesperson said.

"Anyone who has information that will help address problems in the industry is urged to make use of the confidential and secure platform."

Some builders losing confidence in clean-out operation

Another member of the building sector who has clocked up more than 40 years' experience said issues were rife and "there's a wad of hell" that needs to be weeded out.

He said he had begun losing hope in the administration process as he, like others, refrained from coming forward due to a lack of whistleblower protections.

"I was very hopeful at the start but I'm starting to lose a bit of confidence at the moment," he said.

"[There's a] significant culture of staying quiet and [it is] very significant within the CFMEU itself because it can be seen as snitching on their mates."

Another contractor, who also asked to remain anonymous, pointed to recent revelations that CFMEU official Joel Shackleton was re-employed despite being charged with threatening to kill as a perfect example of why those in the industry had refused to come forward to the administrator.

That view was shared by the Victorian contractor.

"I have no faith in the process and assurances given by the administrator because if specifics [were] given they would track us down," they said.

"I want the story to keep being told because not enough is being done at the moment."

Workers discouraged from coming forward

Human relations manager Emily Trevaskis has also worked on major projects in Victoria and has made the decision to speak out.

"The only reason I feel comfortable coming forward is because I'm out of consulting and I no longer work for one of the construction companies," she said.

She said changes were needed because some employers were not encouraging their workers to speak to the administrator.

"Someone needs to make a change for someone to feel safe coming forward and I don't think anyone would feel comfortable coming forward unless it was encouraged by these companies," she said.