Where potential P contamination was detected, the property was tested and reinstated if necessary.
Remedial measures could range from specialised cleaning through to re-fitting a property.
Head of the Eastern Organised Crime Unit, Detective Senior Sergeant Mike Foster, said P manufacturers often resorted to rental or Housing NZ properties.
"I'm picking more often than not, it won't be their own house, because they don't have a financial interest in it."
Mr Foster said the first house that had to be destroyed in the country due to P manufacture was in Napier. However, the number of P labs discovered by police in the Eastern District had "declined rapidly" since 2006.
"We're averaging one lab per year in the district, including Gisborne.
"Labs are becoming more mobile, they can be bundled up in a case... People are becoming a lot more discreet about these things."
Mr Foster said a telltale sign of P manufacture was "very pungent" fumes coming from a vehicle or an address.
"They [the fumes] can cause skin irritations and teary eyes.
"The toxic chemicals associated with P manufacture seep into the walls; the waste is poured down the sinks or poured out on the garden.
"It's really dangerous stuff and it's important for landlords to be aware of the risk."
Gifford Devine solicitor Jim Ferguson said while it was important for landlords to exercise their right to inspect properties on a regular basis, many didn't.
Mr Ferguson said rental properties were attractive targets for P manufacture.
A landlord was not legally obliged to disclose to tenants that a house had previously been used for the manufacture of P or had been contaminated by P.
But if asked, a landlord must answer any contamination queries truthfully.
In 2009, Housing NZ won a test case seeking more than $180,000 in damages from tenants who manufactured methamphetamine in a Napier state house. The house was so badly contaminated that it had to be demolished.