It all started with a simple phone call.

But the result, Australian police say, is by far their largest seizure of methamphetamine - as much as $450 million (438 million Australian dollars) worth of the destructive drug, shipped from southern China and caught in Sydney.

Police have arrested three men in the operation - an Australian, a Singaporean and a Hong Kong citizen - and say they believe the bust has thrown a major international crime syndicate into disarray. More arrests could follow, they add.