Wellington  - New Zealand authorities arrested four Japanese as they brought 6 kilograms of the banned drug crystal methamphetamine into the country from Malaysia this week, police said on Friday.

Worth an estimated 6 million New Zealand dollars (4.4 million US dollars) on the street, it was the biggest haul of methamphetamine intercepted this year.

Detective Inspector Stu Allsopp-Smith said police and customs believed they had broken a significant methamphetamine drug ring with links to Malaysia.

Two Japanese nationals, a 31-year-old woman and a 39-year-old man, had 2 kilograms of methamphetamine in their luggage when they flew into Auckland via Sydney on Tuesday.

Two more couriers, men aged 41 and 50, were intercepted the following day with 4 kilograms of the drug.

Two New Zealanders of Iranian descent, named as Nader Ghaffari, 38, and Fardien Nourian, 42, were also arrested after some of the drugs were taken to a hotel room in Auckland in a monitored delivery.

All six appeared in court charged with importing methamphetamine, which carries a maximum life prison sentence and were remanded in custody. (dpa)