Immigrants are waiting up to 10 weeks for police clearances, which are necessary to apply for residency.
A spokeswoman for immigration New Zealand said a Government-wide increase in demand for police checks since the end of last year, had caused a backlog.
"They are working through this issue and completing police checks as efficiently as they can," the spokeswoman said.
"Immigration New Zealand requests New Zealand police checks, when appropriate, to assess the character of our clients.
"New Zealand police has always provided an exceptional service returning these checks within agreed timeframes and in the majority of cases has exceeded expectations," the spokeswoman said.
"The current turnaround time for a standard police check is up to 10 weeks, however some are able to be completed in as little as a week."
She said Immigration New Zealand was working closely with police to solve the wait time issue.
In June, the Herald reported that schools and childcare centres were short of teachers due to a long wait for police vetting.
At the time, police said there were 53,565 applicants in the queue for checks.
The bottleneck was caused mainly by the Vulnerable Children Act, which from July 1 required all new employees in state-funded jobs who may be alone with, or have primary responsibility for, anyone under age 17 to be vetted.