Australian Federal Police (AFP) say they have smashed a global drug syndicate following what Customs says is the world's largest seizure of the drug ecstasy.

The AFP says 4.4 tonnes of the drug has been seized and 17 people arrested in Victoria, NSW, South Australia and Tasmania this morning.

They are due to appear in court today.

The pills had a street value of $440 million and were found packed in more than 3,000 tomato tins in a shipping container which arrived in Melbourne on June 28, 2007.

On July 24 this year Customs and the AFP intercepted another shipping container in Melbourne, which was found to contain 150 kilograms of a white powder which appeared to be cocaine after testing.

The drugs were substituted for an inert substance and the shipping container was monitored.

The AFP executed 45 search warrants this morning as part of their investigation into an international drug syndicate.

Some of those who have been arrested are alleged to be involved with major drug trafficking in Australia.

The AFP says the investigation also identified a money-laundering operation worth more than $49 million.

Federal Police Commissioner Mick Keelty says the syndicate was a major supplier of illicit drugs to Australia.

"Our estimation and our intelligence indicates that this syndicate is alleged to be involved in something in the order of 60 per cent of importations coming into south-east Australia," he said.

"It is classic organised crime and we have done our best to shut down the syndicate.

"It shows that the Australian Federal Police are taking action to protect the youth on our streets.

"It is another success story in a long line of recent achievements in tackling both domestic and transnational crime."

Federal Attorney-General Robert McClelland says the seizure shows Australia cannot be seen as a soft target for drug syndicates.

"The volume of the seizure indicates that the international syndicates saw Australia as a potentially fertile market," he said.

"We hope that impression has well and truly been smashed."

One of the men arrested was a north-east Tasmanian man who appeared in court this morning.

Federal prosecutors are asking for an extradition order to move the 50-year-old Pipers Brook man interstate.

The Riverina city of Griffith is among the centres where police have raided homes.

Griffith's Mayor Dino Zappacosta says the bust has been a major setback for the New South Wales regional city that has worked hard to distance itself from its past reputation for drug crime.

"Unfortunately limelight will be back on Griffith," he said.

"We have tried for years to clean up the good name of Griffith and as the Mayor I've always tried to talk up Griffith, how it's a wonderful place and this is certainly going to put a dampener on the whole impact that we've had over the years."