A syndicate of Australian criminals - including some '501' deportees to New Zealand - were behind the largest known importation of methamphetamine into the country.

A network of Australians - including a mysterious ringleader known as Big T in Queensland - were the brains behind the largest seizure of methamphetamine in New Zealand history.

More than 500kg of meth was smuggled from a "mothership" - which had been organised by a criminal group in Hong Kong - off the coast of Ninety Mile Beach in Northland.

The huge haul discovered in June 2016 was worth somewhere between $130 million and $150m, if sold at $250,000 to $300,000 per kilogram.

Despite the crucial mistake of trying to bring the meth ashore in the surf of a