The country's top scientists are recommending people do not test their homes for meth contamination unless the police tell them it was a meth lab.

Photo: Contaminated Site Solutions

Housing New Zealand's policy is to evict tenants if their homes tested positive for meth contamination, but the Labour-led government changed that late last year.

A new report by the Prime Minister's chief science adviser, Sir Peter Gluckman, has found that while consuming meth is dangerous, there's never been a documented case of someone getting sick from third-hand exposure to meth.

Sir Peter said there has been an inexplicable leap in logic in New Zealand which saw people worried that even low levels of meth residue created a health risk.

Housing Minister Phil Twyford said hundreds of millions of dollars have been wasted and people unnecessarily evicted based on dodgy information.