New Zealanders failed pre-employment drug tests just 466 times since they were introduced three years ago, Ministry of Social Development figures show.
The Herald sought the figures after Prime Minister Bill English cited the number of young Kiwis failing workplace drug tests as a reason not to further limit unskilled migrant numbers.
English said the Government did not keep records of failed or refused drug tests, but businesses raised the issue with him "two or three times a week".
The ministry's figures, however, showed a relatively low level of jobseekers testing positive for drugs. There were 466 "drug-related work obligation failures" between July 2013 and June 2016 "which may have included a drug test refusal, failure of an evidential drug test or screening drug test".
The ministry was unable to immediately say how many people were tested in total over this period.
But previous responses under the Official Information Act said there were between 29,000 and 32,000 tests a year. That would mean around 0.5 per cent of jobseekers had failed drug tests.
The MSD's figure referred to the number of sanctions, not the number of beneficiaries who failed tests, and could include people who failed tests more than once.
English's claims about drug tests prompted condemnation from Opposition MPs and unions.
Labour's finance spokesman Grant Robertson said it was a "diversionary tactic" to hide the Government's record on job creation and raising incomes.
Ordinary time wages fell in the last quarter and 45 per cent of New Zealanders did not get a pay rise last year, he said.
Robertson described English's defence of his immigration policy as "pathetic" and said the Prime Minister had condemned a generation of Kiwi workers as "druggies".
"New Zealanders might get the impression that Bill English is the one on mind-altering drugs, given the facts about how National has let down workers and young people over the last eight years."
Council of Trade Unions president Richard Wagstaff accused English of using "alternative facts".
"We as a society are better than this," he said.
"By completely overstating the issue of drug use by people looking for work the Prime Minister justifies the widening of immigration policies."
English made the comments after new data out yesterday showed net migration in New Zealand hit a new high of 71,300 people in the last year.
He ruled out further limits on immigration, saying the single biggest driver of net migration was the number of returning New Zealanders, which was at its highest level in 25 years.
However, Statistics New Zealand figures showed a larger proportion of migrant numbers was made up by people arriving on work visas. The number of people in this category was up 4200 to 42,400 in the year to January.
In contrast, the number of New Zealand and Australian citizens arriving over the same period was 37,900, up 1700 on the previous year.