Toilet rolls were used to hide more than half a tonne of methamphetamine, in one of Victoria's biggest drug busts.
The 662kg haul was concealed underneath pallets of toilet paper aboard a shipment that arrived in Melbourne from Malaysia on a sea cargo carrier on October 4.
The 662 packets of ice were found wrapped in green and gold tea foil packaging at the bottom of three of 16 toilet roll stacks.
The drugs have an estimated street value of $559.8 million and could have provided more than 6.2 million street deals.
Four men, who police allege are members of an international organised crime syndicate, were arrested over the bust on Wednesday night and Thursday morning.
They are two Chinese men, both aged 33, a 34-year-old Malaysian and a 32-year-old from Hong Kong.
One of the Chinese men and the Hong Kong man were taken into custody at Melbourne airport as they separately attempted to board flights out of Australia.
Police detained the others at homes in Sunshine North and Box Hill.
All four have been charged with attempting to possess a commercial quantity of a border-controlled drug, which carries a maximum penalty of life imprisonment.
They faced Melbourne Magistrates Court on Thursday and were remanded in custody until their next appearance in February.
The syndicate is alleged have tried to establish a legitimate history of importing toilet paper to sneak the drugs past Australian Border Force officials.
"It was concealed under a legitimate consignment of toilet paper that was imported," ABF commander Clint Sims told reporters in Melbourne.
"This particular syndicate made a number of imports of consignments that were solely legitimate imports of toilet paper to a purported cleaning company.
"These particular ones were, I believe, the third import by the same syndicate."
Police also raided warehouses in Sunshine North, a storage facility in South Melbourne and homes in Box Hill, Glen Waverley and Blackburn, seizing evidence of the imports and mobile phones.
Commander Sims said the bust was only possible because ABF officials received credible and timely intelligence from a number of sources.
"While this is a very significant seizure, it is a drop in the ocean compared to everything that is flooding into Australia," he said.
Victoria Police Detective Superintendent Dan Ryan said Australia had an insatiable appetite for illicit drugs.
"Our use of methamphetamine is unmatched by any other nation in the world," he said.
"In 2022, Victoria Police conducted 172,000 roadside drug tests and detected over 10,000 positive results."
Police have not ruled out further arrests over the bust, with investigations ongoing.