A public examination will be held into the collapse of two major Queensland construction companies which the Government says left hundreds of small businesses, subcontractors and suppliers unpaid.

Key points: Cullen Group and One Home collapsed, owing creditors millions

Cullen Group and One Home collapsed, owing creditors millions The State Government says small businesses and subcontractors bore the brunt

The State Government says small businesses and subcontractors bore the brunt A $300,000 inquiry by the regulator will seek to find out where the money went

The Queensland Building and Construction Commission (QBCC) is contributing $300,000 for inquiries into both Cullen Group and Queensland One Homes, which are said to have had "significant" ramifications on the construction industry.

Cullen Group collapsed in December 2016, leaving 500 creditors owed more than $18 million, while Queensland One Homes was left owing $6 million when it went into liquidation in July 2017.

Hayden Quaife's roofing business had been subcontracted to work on the multi-million-dollar Boheme apartment complex on the Gold Coast for Cullen when he found out it had gone into administration.

"We first got told Cullen Group went into administration just as we went into the holiday period," he said.

"We'd all finished up for work and we got a notification by email that Cullen had gone into administration.

"It wasn't good — it's not fun when you hear that, when you lose so much money."

Mr Quaife said he lost about $250,000, which had the potential to wipe out his business.

He was not alone.

When work was underway on the Cullen Group's Boheme apartment complex in 2016. ( Supplied )

Owner of concrete formwork business Tom Caelli said he lost more than $500,000 in the collapse after finishing work on the same project, as well as another complex in Springwood.

"I know a lot of people who have packed up, but we want to push through as much as we can," he said.

"We've got 120 employees and it's a company that my grandfather started.

"I don't want to pack up the family business that's been around for three generations."

Both business owners said they were dealt a double blow when they were contacted by solicitors on behalf of the liquidators who claimed they received preferential payments — something they both strongly deny.

"For someone to come in and say that they're trying to help but still make us spend money on solicitors and prove our innocence when you can clearly see we are innocent and have already copped a beating … but we're pushing through it," Mr Caelli said.

"I've even had insurance companies scare away suppliers — they've told suppliers to watch out for us because we have lost so much."

Minister for Housing and Public Works Mick de Brenni said small businesses bore the brunt.

"In both of those cases, hundreds of small businesses, subcontractors and suppliers went unpaid," he said.

"When that happens, it destroys those small businesses and it ruins families.

Inside a complete apartment at the Cullen Group's Boheme apartment complex. ( www.cityvillage.com.au/boheme/ )

"This public examination will see witnesses examined in court and what they'll be looking for is threads to pull to find where that money went.

"Those millions of dollars should have gone into the pockets of Queensland small businesses — instead it's gone somewhere else.

"It's important we look back to these significant collapses and identify where exactly the money went — what went wrong?"

As part of the examination, directors of the two failed companies could be forced to appear before the Federal Court to give evidence.

Just last week, hundreds of workers were left in the lurch after central Queensland construction company JM Kelly went into administration.

QBCC Commissioner Brett Bassett said his office had received a number of complaints in the last 18 months related to Cullen Group and Queensland One Homes.

"There were tens of millions of dollars that were lost as a result of these two companies going down," he said.

The QBCC is now using available data for an algorithm to predict if a business is headed for disaster.

"As the regulator of the building and construction sector, we need to make sure that we have early warning and early detection systems in place — that we now have — to help us more proactively identify companies that might be tracking towards financial distress."

But Mr Quaife said he was not hopeful of seeing the money he was owed.

"That's the administrators' job, to try and get the money back from the creditors," he said.

"I've been through a lot of these in the past and I've never seen a cent back in a subbie's pocket ever — it's all been chewed up by administrators and solicitors … if there's ever money to get back."