"Unfortunately, it is increasing, and when we turn over a crime organisation we are recovering more and more all the time," he said.
At the same time there appeared to have been less local production compared with earlier years, including 2003 when police were reported to have uncovered almost 150 clandestine P-making laboratories throughout New Zealand, many in residential areas.
Mr Reilly, who has been involved for more than a decade in attacking the problem from the demand end, said: "We thought we were through it. There was a lot of good and productive work that had gone on, and that it was mainly just the residual user, but it has come to visit us again.
"It is supply driven," he said. "Somewhere or other the code has been cracked and there are now some big players, which means that if somebody wants it, then someone's going to find a way of getting it to them."
Mr O'Reilly warns against hyping the issue up.
He said "quiet pro-active responses" using all resources available, including health and mental health services, and "compassion" in reducing the need for methamphetamine were needed.