The Government is looking at developing national standards for companies carrying out methamphetamine contamination testing on homes.
Building and Housing Minister Nick Smith says there needs to be consistency around the point at which the level of contamination is deemed a risk, as well as the repair work that is required.
"The testing business has developed into quite an enterprise in its own right," he told reporters.
"That's why it's important that we have standards and important that those people who are doing the testing are acting genuinely in the public interest and not using the fear to effectively milk the housing sector for a bit of cheap profit."
Meanwhile, Dr Smith said the Government could pick up a member's bill being drafted by National MP Andrew Bayly which would give landlords stronger powers to test their properties.
The Bill would also make it obligatory for landlords to provide rental accommodation free of contamination.
"The proposed changes specifically enable landlords to enter premises with appropriate notice for the purposes of testing for P and other dangerous substances," Mr Bayly said.
"They also reinforce that tenants can be removed when a house is uninhabitable, and ensured contaminated houses aren't tenanted."
In February this year Social Housing Minister Paula Bennett said at least 370 state houses were vacant because of methamphetamine contamination.
Mr Bayly's bill will go into the members' ballot, and won't be debated in parliament until it's drawn.
There are more than 70 in the ballot and one or two are usually drawn every second Wednesday parliament sits.