Vic police smash Melbourne drug syndicate

A Vietnamese crime syndicate has been smashed as a four-month police operation culminated in raids across Melbourne's north and west.

Nine people, men and women, were arrested during raids at 13 properties on Friday.

Half a kilogram of ice, a homemade firearm, $10,000 cash and vehicles were among items seized.

It took the total amount of drugs linked to the group, and seized during Operation Kanji, to a haul with a street value of around $9 million.

Police say the syndicate had international links and was connected to other large-scale Victorian crime rings.

Assistant Commissioner Stephen Fontana says police began investigating the group over heroin trafficking, and then found they were peddling other drugs as well.

"We've basically broken up a significant organised crime syndicate, of Vietnamese descent, that have been involved in the distribution of cannabis, heroin, cocaine, ice and other substances," Mr Fontana told reporters on Friday.

"They are pretty well connected, it is well organised and it's been operating for quite a while."

About 2800 cannabis plants and 25kg of dried material, worth a total $8 million street value, were seized in earlier raids at factories and grow houses.

Mr Fontana says a number of the people arrested on Friday will likely be charged, but the investigation is ongoing.

"We've got a number of individuals we will be speaking to, and interviewing, and they will most likely get charged," Mr Fontana says.

"We've got searches underway, we'll probably find other evidence and other leads and we'll continue on."

Melbourne's north and western suburbs were the focus of the raids on Friday, with homes and commercial properties at Braybrook, Sunshine West and Preston searched.

VICTORIA'S LATEST DRUG SYNDICATE BUST

* Drugs worth $9 million street value seized over four months

* 2800 cannabis plants, 25 kilos dried material worth total $8 million

* More than half a kilo of heroin, worth $773,000

* More than a kilo of ice, worth $884,000

* Cocaine worth $22,400

* Nine arrested on Friday

* Ice, firearm, $10,000 cash and vehicles nabbed in latest raids.