Iodine is used in the manufacture of methamphetamine.
"As our investigation unfolded we identified an extensive network involved in the importation of methamphetamine, GBL, MDMA, and pre-cursors used in the manufacturing of methamphetamine," he said.
The investigation uncovered a significant drug dealing network centred in the Bay of Plenty and extending into the Waikato region.
Those arrested will appear in Whakatāne, Hamilton and Rotorua District Courts in the coming days.
Today, police also seized methamphetamine and MDMA, LSD, cannabis, cash, Bitcoin, a ute, and a number of electronic items used in coordinating drug importation and distribution.
"These illicit drugs cause a significant amount of harm in communities across New Zealand," Shields said.
"They destroy the lives of users, as well as hurting users' families and loved ones."
He said police were confident the arrests would result in a major disruption to the supply of meth and other illicit drugs in the Bay of Plenty and Waikato regions.
Those affected by drug addiction can seek help through the Alcohol and Drug Helpline on 0800 787 797, or free text 868.
Anyone with information about drug offending in their communities is urged to contact Police. Information can also be provided anonymously via Crimestoppers on 0800 555 111.