(CNN) US authorities have confiscated almost a billion dollars' worth of methamphetamine bound for Australia in the largest-ever seizure of the drug on American soil, Australian police announced Friday after a joint operation.

Around 1.7 tons of meth was seized in California on January 9 by US authorities, along with smaller amounts of cocaine and heroin, police said. The estimated street value of the meth was 1.29 billion AUD, or $911 million and was also the largest-ever shipment intended for Australia.

The drugs were to be shipped to Australia hidden inside electronics equipment.

On Thursday, police in Australia arrested six people in the states of Victoria and New South Wales allegedly involved with the US-based crime syndicate believed behind the record-breaking shipment.

"Hundreds of thousands of dollars of proceeds of crime was located during the search warrant in Woodstock, and about 6.5kg of (meth) was found at a property in Keilor Downs," police said in a statement.

Three of those arrested in Australia will appear at Melbourne Magistrates Court later on Friday.

The drugs were seized in California on January 9 by US authorities. The Australian Federal Police and Victoria Police arrested six people in the states of Victoria and New South Wales in south-eastern Australia Thursday.

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