Updated

New Zealand police say they've made the nation's largest-ever methamphetamine bust after pulling over an RV loaded with a half-ton of the drug, which was likely manufactured overseas.

Police said Tuesday they stopped the vehicle near Kaitaia in the country's far north on Sunday and found it contained multiple suitcases and bags stuffed with plastic baggies filled the drug.

Police say they recovered 448 kilograms (988 pounds) of methamphetamine, with an estimated street value of 448 million New Zealand dollars ($316 million).

Police say the driver of the RV and two other men were arrested and charged with importing and possessing methamphetamine. The men made an initial court appearance Tuesday and remained in jail.

Police say they believe the drugs were retrieved offshore from Ninety Mile Beach.