Twenty people have had their benefits cancelled or suspended since a policy introduced in July last year made drug-testing compulsory for some jobs.
Beneficiaries have to undertake and pass a drug test if an employer or training provider asks for one as part of the application process.
Five benefits have been cancelled, 15 suspended and 32 reduced.
About 29,890 beneficiaries had been referred to drug-testable jobs by the end of June this year.
The Ministry of Social Development said the policy may have had a pre-emptive effect, as it believed people who know they may be required to pass a test are stopping their drug use.