Twenty-six Bay state houses have tested positive for methamphetamine contamination in the last 18 months.
Housing New Zealand chief operating officer Paul Commons said in the 2014/15 financial year, 18 homes had tested positive for methamphetamine (P) contamination in the Bay of Plenty, and eight so far in 2015/16.
In the 2013 calendar year, just eight state houses tested positive for the drug nationwide.
Mr Commons said as a responsible landlord, Housing New Zealand had a policy of not knowingly letting tenants live in a property with readings above the Ministry of Health's set levels.
"Over the last few years, Housing New Zealand has placed greater focus on identifying homes where P may be used, or may have been used in the past, rather than manufactured.
All of Housing New Zealand's front-line staff were trained to recognise signs of possible meth manufacturing and use, how to deal with tenants who may be affected by meth, and also learned conflict management skills to use in these situations.
Properties suspected to be contaminated would always be tested and remediated as necessary, and costs were covered by Housing New Zealand.
Mr Commons said the corporation had a "zero tolerance approach" to the use or manufacturing of meth, or any other illegal activity, in its homes and would move swiftly to evict tenants where it happened.
"We communicate this very clearly to all our tenants, and will pursue tenants for costs associated with property damage caused through recreational drug use or the manufacture of drugs."
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The issue of testing all vacant Housing New Zealand properties for methamphetamine contamination was currently under consideration.
Mr Commons said contamination from P use was preventing vulnerable people on the social housing register from getting access to a home as cleaning and remediation could take up to three months in serious situations.
Eight properties in the Western Bay and seven properties in Tauranga were registered by the council as being contaminated by methamphetamine between 2013 and 2015.
Tauranga City Council communications advisor Marcel Currin said when police notified the council about a contaminated property, that information was placed on the property file along with any subsequent reports relating to further testing and contamination.
Tauranga Property Investors Association president Grant Harris said "members of the association carried out regular inspections of their rental properties which would assist in identifying if P was being used or manufactured".
"A good landlord will regularly have property inspections of their rental properties and so if there was suspicious activities going on it may be identified for example by paraphernalia around the property.
"If a tenant was smoking P that could cause considerable contamination as well. Either the manufacturing of P or the use both cause contamination."
Mr Harris said he had not faced issues with drug use in his rental properties but knew of members who had seen contaminated houses as an investment opportunity.
"I'm aware of some members who have purchased properties after carrying out their due diligence and knowing they are contaminated properties ... that need to be decontaminated.
"It's a very specialist area for investors," he said.
"But of course they are making sure they are buying it at the right price to factor in decontamination costs, which can be significant depending on nature and extent of contamination."