Labour says 240 state homes sitting needlessly empty will be back in use after a new study shows living in a former meth house poses no health risk.

Housing Minister, Phil Twyford says whānau wrongly kicked out, should top the waiting lists for new homes.

Labour also says that the study means tens of thousands of houses were needlessly tested and cleaned, costing millions, in the middle of a housing crisis, while large numbers were demolished or left empty.

In response, Housing NZ has moved the trace levels of meth to ten times higher than the previous standard.