Some of the 494kg of methamphetamine landed on Ninety Mile Beach on June 19, 2016.
Two people have been found guilty for their parts in the country's largest ever methamphetamine bust, which saw half a tonne of the drug delivered to Ninety Mile Beach.
Selaima Fakaosilea, 30, and Stevie Norua Cullen, 36, have been on trial in the High Court at Whangārei for the past seven weeks charged with importing methamphetamine and participating in an organised criminal group.
In June 2016, police found 449kg of methamphetamine in a campervan at Totara North. A further 52kg was found buried in the sand dunes on Ninety Mile Beach. The 501kg haul had an estimated street value of almost half a billion dollars.
Six people have already pleaded guilty in relation to the operation.
The jury hearing the case retired to consider their verdicts on Monday afternoon, returning just before noon today, and found the pair guilty on all charges.
Cullen did take the stand and told the court he thought he was on a trip to scatter his friend's ashes at sea and that he knew nothing of a drug importation and was not involved in an organised criminal group.
The Crown said Cullen had full knowledge of what was happening and was responsible for logistical tasks relating to the importation of the drugs.
Those tasks included hiring hotel rooms and being present and participating in meetings when plans were discussed. He was also involved in a failed launch on June 9, 2016.
Evidence was produced that Cullen researched places to launch a boat, liaised with Far North locals and was present when the boat with methamphetamine on board landed on the beach.
Fakaosilea's defence was she was not in Northland when the drugs came ashore and she had no knowledge of the drugs or their importation.
The Crown said Fakaosilea had an embedded role in the criminal group and had rolled up her sleeves and got involved by organising hire vehicles, the transportation of two Asian men to the Far North and satellite phones.
During the trial the jury heard from many witnesses including three who were considered experts in their fields of fingerprinting, electronic devices forensics and an analyst from Environmental Science and Research who confirmed the drug was methamphetamine.
Three witnesses also gave evidence via closed circuit television.
Justice Gordon told the jury before they went out that special care would be required given the circumstances of the trial as it was a huge quantity that the Crown alleged had been imported.
"Some of you may have strong views about methamphetamine. It is most important that you put them to one side and don't involve them in deliberations.
"It's easier said than done but there is no room for these feelings in this trial."