Several sub-contractors who worked on the expansion of the Perth Airport say they are owed hundreds of thousands of dollars from the project.

Key points: Airport construction company Alcom Fabrications goes into administration

Airport construction company Alcom Fabrications goes into administration Sub-contractors claim they are owed hundreds of thousands

Sub-contractors claim they are owed hundreds of thousands Union says scenario highlights flaws with construction regulation

The new terminal was met with much fanfare when it was unveiled late last year, but the project has been marred by cost overruns and delays.

Up to a dozen companies associated with the major airport expansion are believed to have folded as a result — including Alcom Fabrications which went into administration in February with more than $11 million in debts.

Alcom's administrator is investigating whether the company knowingly made false statements about its finances, allowing it to rack up debts it ultimately could not pay.

Alcom has pointed the finger at the project's head builder, Built Environs, claiming the larger company owes it more than $2 million.

While Built Environs has launched a multi-million-dollar lawsuit against the airport authority — blaming the operator for delays that held up the project for more than a year.

Sub-contractor now 'back to square one'

Sub-contractor Glenn Golledge, who was working for Alcom across several projects, has a stack of bills totalling $1.1 million.

Mr Golledge said that spelled the end of the financial security he had worked hard for many years to build up.

"My business was flourishing, went big real quick and was going well," he said.

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"Scored this contract and it basically sucked me dry, the company dry, my bank accounts dry, overdraft dry and major stress on my marriage. So yeah, devastated."

Sub-contractors John Hall (L) and Glenn Golledge say they were promised money which never came. ( ABC News: Courtney Bembridge )

The hardship is not just financial.

Mr Golledge had moved to an office job and, importantly, out of the sun after a skin cancer scare. But when the bills piled up he had to go back to working outside.

"This has put me back to square one, I'm back out on the tools, back in the sun where I'm not supposed to be but I've got to do it, I've gotta get myself out of this," Mr Golledge said.

He is not alone, dozens of sub-contractors tell a similar story, including John Hall.

"All my savings, everything, they're all gone," he said.

"We suffer and it's as if 'we're in the building game, you have to expect this' and I'm going no we shouldn't have to expect this."

Mr Hall said the sub-contractors were paid small amounts to ensure they kept showing up to work.

He said they were promised the money would come but "then at the end there was nothing, just walk away and thanks very much".

Court battles likely as creditors chase money

Mick Buchan from the Construction Forestry Mining and Energy Union says the case highlights deep flaws in the regulation of the construction industry.

"There wouldn't be many at all that wouldn't have a story like this," he said.

"The big players will just say 'well take us to court now'.

"There's not many construction sub-contractors that could afford the legal battles with the big end of town for chasing up those type of dollars."

Another of Alcom sub-contractors, Adrian Koopman, launched legal action against the company before it folded to try to get back the money he is owed.

He now wants the company's directors to be held personally responsible.

"I've contributed to this build out of my pocket for these big corporations, I have trouble getting my head around that — why I paid for myself to build this airport," he said.

"This is the most high-profile job that I've done so far, I didn't want to walk out on this job.

"It's a beautiful building but it's cost me dearly and along with my co-workers."

The findings from Alcom's administrator's investigation will be handed over to the corporate watchdog, the Australian Securities and Investments Commission.