Building Minister Nick Smith says tighter rules for businesses which test for meth contamination will be in place by the end of the year as real estate industry insiders report increasing numbers of cowboy operators milking owners.

Homeowners continue to shell out millions to decontaminate properties while prospective home buyers are making last-minute discoveries that their potential home was once a haven for the drug.

Industry insiders say 40 per cent of homes that are tested come back positive for methamphetamine and that is on the increase as public awareness builds about how widespread the issue of P contaminated homes really is.

Harcourts chief executive Chris Kennedy yesterday called for the Government to "urgently set in place standards around the methamphetamine testing industry" after being inundated with reports of varying levels of competency of P testing companies.


"In my investigations I've found that the testers and cleaners have differing viewpoints on the severity of contamination and the methods for decontamination.

"We need some standards put into place to protect consumers and the Government needs to take the lead on this."

Agents were required to make full disclosure if they discovered the drug had been used at a property, but Mr Kennedy said the buyer still had to do their own due diligence.

Dr Smith said yesterday the Government would have new national standards in place by the end of the year.

Late last year, the Government set aside money from the Proceeds of Crime Act to develop the standards for companies that test and decontaminate P tainted homes.

Dr Smith said the standards would cover testing methods, a maximum contamination threshold, and the level of work required once that threshold had been reached.

However, Dr Smith ruled out making testing mandatory.

"To make it mandatory over all 200,000 plus property sales per year would add a cost to the sector that I think would exceed the benefits."

Rental properties could also be tackled by a member's bill to be introduced by National MP for Hunua Andrew Bayly.

The bill would give landlords the right to enter properties with notice to test for P, and to remove tenants if a house was uninhabitable.

It would also prevent landlords from knowingly renting P-contaminated properties, and require them to inform tenants as soon as contamination was revealed.

John Gray of the Home Owners and Buyers Association welcomed new standards. He said he was often fielding reports of either too much or not enough work being done on suspected P-riddled homes.

There were cases before the courts as bungled property deals have swung back to bite the vendor and their agent.

"There is a very serious problem because we are dealing with many members who have suffered physically, mentally and financially as a result of buying a home that was contaminated."