Half tonne of ice in Sydney container

An alleged Sydney drug syndicate has been toppled, police say, after they discovered half a tonne of "absolutely pure" methamphetamine in a shipping container falsely declared as clothing.

The 500 kilograms of ice, with an estimated street value of $375 million, was uncovered by Australian Federal Police and border force officials at Sydney's container examination facility in June.

Detectives arrested a 35-year-old man as he walked down the street at Wolli Creek about midday on Thursday.

They then swooped on a Hurstville shopping centre where they arrested a 55-year-old Canadian.

Two more men, aged 33 and 36, were arrested at homes in Carlton and Rhodes.

Police allege the group formed a syndicate headquartered in Sydney to distribute the "corrosive" drug across Australia.

"It was an absolutely pure form of crystal methamphetamine," Acting Assistant Commissioner Stuart Smith told reporters on Friday.

"(Ice) is corrosive to families, it breaks down the fabric of society."

The operation was designed to remove segments of the supply chain which ran the drug as far as Western Australia, Mr Smith added.

The arrests came as the syndicate was breaking down the 500 packages of the substance and moving them around Sydney in preparation for interstate distribution.

Mr Smith said the enterprise was highly sophisticated and its international links appeared to span a third of the world.

The accused 35-year-old and 55-year-old were charged with supplying a large commercial quantity of drugs and criminal group charges. The 33-year-old was charged with criminal groups charges.

They were all refused bail and ordered to appear in Sutherland Local Court on Friday.

The 36-year-old man was charged with dealing with the proceeds of crime and bailed to appear before Burwood Local Court in August.

Mr Smith did not rule out further arrests and charges.

The arrests were made by Strikeforce Fergerson, set up in 2018.