An industry expert believes methamphetamine-infected homes could be the next 'leaky homes' crisis.
The head of commercial meth cleaning service Envirocheck says up to 20 percent of kiwi homes could be infected, with half of those at levels above the Ministry of Health’s guidelines.
Envirocheck head David Kilburn says it has the potential to be a huge problem.
"I think it's a billion dollar problem," he says. "Some of those houses are going to cost $100,000 to put right."
Mr Kilburn was told the Ministry of Health estimates around 50 homes are infected every year, but he believes that’s a gross underestimate.
"We could find 50 houses contaminated every three months and we're just one company."
Mr Kilburn is warning homeowners that P can be found anywhere.
"[People tell us] the people we bought it off were an elderly couple, and they'd owned it for twenty years, how could there be meth in the house.
"[I tell them] what about your guests? Can you vouch for every single one of them? What about the elderly couple? Did they have any grandchildren come stay with them? Was one of their grandchildren a meth head?
"You just cannot be certain that meth hasn't come into your home. They may have done that outside and then walked in and the fumes have followed them in."
Meanwhile, Social Housing Minister Paula Bennett is shocked nearly a quarter of homes in a brand new Christchurch housing development have been contaminated with meth.
In most cases, the tenants were single mothers with small children, some as young as nine months old.
Minister Bennett says police and Child, Youth and Family have been involved.
"It certainly shocks me that these are young children living in the house, out of 19 brand new homes in June last year. By February this year they'd been tested and four of them had traces of methamphetamine."
Two of the tenants were moved immediately and another two are in the process of being evicted.
The Ministry was alerted after neighbours told police they thought some of the houses were being used for drug dealing.
Ms Bennett says more than 400 houses are currently out of the state housing pool because of P use.
"In the last six months of last year we spent $5.8 million on testing and remediation but that is going up by the millions, and they're forecasting to spend a lot more than that this year," she says.
She says Housing New Zealand is now dealing with far more methamphetamine use in its houses.
"There are real consequences for those that abuse themselves and these houses like this."