IAG has the AMI, State, NAC, NZI, Lumley and Lantern insurance brands and covers more than half all New Zealand's properties.
Hart said IAG insured about a quarter around half of the country's 450,000 rental properties. Based on his statement, that amounts to more than 225,000 rented properties.
No devices were available to warn landlords that P was being smoked in a property, only to warn of meth labs, he said. Landlords should test properties between tenancies, he said.
A new meth standard is being developed in New Zealand. Last year, the Ministry of Health recommended a different level be used to guide clean up of properties where meth had been used compared to meth lab homes, IAG noted.
Its report recommends a level of 0.5 micrograms for lab homes, 1.5 micrograms for carpeted homes where it has only been consumed and 2 micrograms for non-carpeted homes, IAG said.
"At larger quantities, methamphetamine is hazardous, and its manufacture dangerous. In homes where the drug has been cooked, methamphetamine residue is the 'canary in the cage' warning for the presence of other toxins, such as solvents and heavy metals," IAG said.
However, in properties where it had only been smoked, "methamphetamine means potential exposure to low concentrations of the drug on surfaces with a much reduced risk of toxicity", IAG said.