A violent Mexican cartel is one of several targeting Australia's drug market, say local and international police who busted a record NZ$1.3 billion haul of ice headed to the country.
The seizure of 1.7 tonnes of the drug in California on January 9 was also the biggest ever domestic seizure of methamphetamine in the US.
The quantity could have produced more than 17 million drug deals, with an estimated street value of about NZ$1.35 billion, police said.
"This is the largest seizure of ice bound for Australia ever. This is the largest seizure ever located in the USA," Australian Federal Police Assistant Commissioner Bruce Hill told reporters in Melbourne on Friday.
"We have averted a tsunami of ice to Australia."
Another 25 kilograms of cocaine, worth about NZ$9.95 million, and 5kg of heroin valued at NZ$2.72 million, was also uncovered in the shipment of 850 car audio parts.
It has led to six arrests in Victoria and NSW.
Police believe the Mexican cartel has links to Australian-based outlaw bikie gangs but would not give further detail.
"This is a serious warning. We now believe Mexican cartels are actively targeting Australia, they have been sending smaller amounts of ice over the years but this is now flagging the intent that Australia is now being targeted," Mr Hill said.
"This cartel is among one of the most powerful and violent drug trafficking syndicates in the world."
He said police dismantled a "very sophisticated operation" on Thursday, "averting a disaster for this country".
"The Australian public who are consuming ice and other illicit drugs are assisting organised crime to flourish," Mr Hill added.
"We continue to pay top dollar for drugs in this country. This is an absolute drawcard for organised crime."
Police arrested six people yesterday, allegedly involved with the US-based organised syndicate behind the shipment.
Officers raided properties across six Melbourne suburbs yesterday and today with four people arrested.
Three fronted court today on charges including attempted drug importation and possession.
Tuan Ngoc Tran and Americans Nasser Abo Abdo and Leonor Fajardo, all residents of Melbourne, faced Melbourne Magistrates Court on today.
They were remanded in custody to face court again on June 17, as charges were pending against a fourth person arrested in Melbourne.
As part of the Victorian raids, NZ$524,126 in cash and about 6.5kg of ice was found, police said.
Three raids in Sydney yesterday led to the arrest of two men aged 25 and 31, and the seizure of 2kg of cocaine.
They will be extradited to Melbourne to face court.
Five search warrants have also been executed in British Columbia in Canada where a significant amount of property, believed to be proceeds of crime, have been seized.
The investigation began after police intercepted a vehicle in northern Victoria last year, and found 25kg of ice. The suspect was linked to organised crime with outlaw motorcycle gangs.
The matter was referred on, eventually leading to the international operation. Investigations are ongoing.