He said some landlords preferred to look the other way if the issue wasn't causing any obvious problems.
"They don't want to know if all looks OK but my advice is do an assessment of risk on the property.
"The long-term consequences of P can be dire."
He said the cost of testing used to be too expensive and had minimal quality.
"Lab-based testing used to cost between $2000 and $3000. Now it's more affordable. We've seen an increasing number of rental agencies placing demand on our methrisk management programmes. The industry wants to do something."
NZ First MP Darroch Ball said landlords such as Housing NZ were acting unlawfully by placing tenants into contaminated homes.
"More than 40 per cent of state houses tested for contamination tested positive yet HNZ is knowingly putting thousands of families at risk by not testing before they move in."
A HNZ spokesperson says they do not carry out random tests and rely on agencies such as the police to alert them of suspected drug use.
"To protect the health and wellbeing of our tenants, HNZ will test for methamphetamine (P) contamination when we have reason to believe a property is contaminated with P. If a property is positive with levels above that of the Ministry of Health guidelines we would not allow our tenants to remain living in the property and will discuss next steps with them. We do this to protect them, their family, and our communities."
The spokesperson also said if tenants were not responsible, they would be supported into another HNZ home. But Manawatu Tenant's Union Kevin Reilly said innocent tenants were being blamed for drug use despite no police prosecutions.
"One of the concerns is now those tenants in state housing have to pay the costs for the home to be decontaminated ... the person on the tenancy agreement is the one responsible for the property, while the unknown person who consumes the drug may not ever be prosecuted.
"Central government has to take a lead and change the law so those on the tenancy agreement, if deemed innocent of P use, are not liable for the costs."
Mr Stratford said the only way to determine if the tenant was the one responsible was to test the property prior to them moving in.
The tenancy tribunal states landlords who rent contaminated properties are in breach of their obligation to provide a property in a "reasonable state of cleanliness", as stated in section 45(1)(a) of the Residential Tenancies Act 1986.
