US authorities have intercepted a record 1.7 tonnes of methamphetamine worth $1.29 billion bound for Australia.

The drugs were found hidden inside 850 car audio parts.

“We have averted a tsunami of ice to Australia,” Australian Federal Police Assistant Commissioner of Organised Crime Bruce Hill said.

“This is the largest seizure of ice bound for Australia ever. This is the largest seizure ever located in the USA,” he told media in Melbourne on Friday.

“With this seizure we have stopped more than 17 million drug deals from reaching our streets,” Victoria Police Crime Command Assistant Commissioner Tess Walsh said.

Assistant Commissioner Hill said a joint Australia-US investigation was kickstarted by the Victorian Joint Organised Crime Taskforce (JOCTF) who had gathered intelligence about an alleged planned large-scale drug importation by a suspected syndicate operating out of California.

“This is the biggest ever seizure of methylamphetamine – more than 1.7 tonnes – stopped before it had a chance to reach Australian streets.

Police believe a violent Mexican cartel – one of several targeting Australia’s drug market – has links to Australian-based outlaw bikie gangs.

“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,” Assistant Commissioner 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”.

“By stopping this, we have ensured criminals will not profit from the immense pain these drugs would have caused our community,” he said.

US Acting Ambassador James Carouso said the “historic seizure” highlighted how important it was for law enforcement agencies to work together.

“Every day, US and Australian law enforcement officers work together to keep us all safe.”

The drugs were allegedly seized in California by US authorities last month before they could reach Australian shores.

The shipment included the following drugs (their estimated street values based on their value if they had reached Australia):

• 1728kg of methylamphetamine, estimated to be worth more than $1.29 billion
• 25kg of cocaine, worth an estimated $9.5 million
• 5kg of heroin, worth an estimated $2.6 million

Officers from the Australian Federal Police and Victoria Police arrested six people on Thursday allegedly involved with the US-based organised syndicate investigated over the record-making shipment.

An American man, 52 and woman, 46 from Woodstock, and a man, 31, and woman, 29, from Keilor Downs were arrrested. Three were set to face Melbourne Magistrates Court on Friday.

Hundreds of thousands of dollars in proceeds of crime was allegedly located during the search warrant in Woodstock and about 6.5kg of methylamphetamine was allegedly found at a property in Keilor Downs.

Two Sydney men were also arrested and face extradition to Victoria in the coming days.

Assistant Commissioner Walsh said the large-scale drug importation would have had profound impacts on the Victorian community and beyond.