Concerns have been raised about the safety of homemade bushfire bunkers installed to provide people with a last-minute refuge from bushfires.
The Black Saturday royal commission found people died in bushfire bunkers, leading it to recommend national regulations for personal fire shelters.
Deputy commissioner Neil Savery from the Victorian Building Commission (VBC) says the bunkers are illegal and dangerous.
"It's an illegal structure, it sounds inherently unsafe and potentially is a death trap for the individuals that may go in there," he said.
"We know from the experience of the royal commission that some people did perish in what they thought were bushfire bunkers that they'd built themselves.
"Whether it was secondary to a wine cellar or a building container shipping container, they died, and not necessarily that they died of fire. They suffocated, the oxygen was extracted out of the bunker because it wasn't airtight or the heat essentially killed them."
So far, only one company's fire bunker has passed the CSIRO's rigorous testing and been accredited by the VBC.
What concerns authorities is that some companies have built bunkers that do not meet these standards.
One company, Fire Proof Shelters, has been promoting its products online.
Manda Canny, who lives in far east Gippsland and wanted more protection after the Black Saturday bushfires, had one of the bunkers installed.
But despite the brochure that clearly marketed their products as personal fire shelters, their invoice was made out for a storage shelter.
"They told me that their bunker was way superior than any others, it'll be the first cab off the rank to be accredited, and it's only a matter of time that they get it accredited," she said.
"They even said to us 'unfortunately they're not meant to sell them but there was a way around it and that was to invoice us for a storage shelter'.
"We agreed to that but we were under the full understanding that as soon as their accreditation came through, they'd send us the appropriate paperwork."
However, Fire Proof Shelters never had its product accredited.
Mr Savery says that he has heard stories of companies installing bunkers on the promise that they are about to be accredited.
"I think that's almost unethical that they would be doing that because the product that they're putting out there now is not a legal structure," he said.
"And if it does achieve accreditation then it might be a different product to that which they've put out right now."
Left feeling 'violated'
7.30 has made repeated attempts to contact the men behind Fire Proof Shelters, Craig Morrison and Andrew Kelly, but has received no response.
But in a letter to Ms Canny's neighbour, Pauline Buchanan - who also had a bunker installed - Mr Kelly rejected a number of their claims.
The company claims that it warned Ms Buchanan and Ms Canny that their product brochures were outdated.
"[The brochures] were only given out purely for the picture/design of what our Fire Resistant Storage Shelter looked like and nothing else," the letter said.
"At no time did we tell you that we could not sell the Fire Resistant Storage Shelter as a fire shelter.
"What we did tell you was that we were not legally able to sell you a Personal Fire Shelter. We sold you our Fire Resistant Storage Shelter."
Ms Canny and Ms Buchanan lodged a civil claim with the Victorian Civil and Administration Tribunal (VCAT), but 18 months later they are still hoping for a resolution.
"You feel pretty violated really," Ms Canny said.
"To me it's almost a criminal act what they've done - we've basically got nothing for our money.
"We'll keep battling on but hopefully at the end of the day other people won't get sold dodgy bunkers."