The increase in budget for detecting drugs at the border is paying dividends.

This year's budget set aside $8.6m to stop drugs entering New Zealand.

It's resulted in 1,634 seizures of class A, B and C drugs by Customs in the first half of this year.

Wagner said there's no silver bullet to stopping drugs at the borders but rather a multi-layered approach is needed.

"Our increased investment at the border, the work that we're doing with our dogs, with our customs officers, with our intelligence internationally, and our targeting is really paying in benefit.

"It's really important that we do stay one jump ahead and that we work with our international partners, and we're doing that."