The operation to break the drug syndicate gained momentum on Tuesday when police stopped a car in Brussels Crescent, Rooty Hill, and say the male driver, 42, was in possession of two grams of the drug ice.

Police executed a search warrant at a house in Tivoli Place, Doonside, on the same day and say they uncovered stolen property and drug paraphernalia.

Four people were arrested on Tuesday: two men aged 42 and 26 and two women aged, 47 and 35.

Another arrest followed on Wednesday night after police stopped a vehicle in Canley Vale.

Police say that while searching the 31-year-old male driver and his car, they found 13.5 grams of ice, cash, 10 mobile phones and an extendable baton.

At the man's home in Canley Vale, police found 800 grams of ice, a loaded .22-calibre semi-automatic pistol, a loaded .22-calibre "key ring" gun, and equipment relating to drug supply.

But there was more to come: investigators raided a storage unit at Artarmon and, pending drug analysis, said they found what appeared to be 14 kilograms of ice, 11.5 kilograms of "black tar" heroin and two kilograms of brown heroin hidden inside fruit juice boxes.

They arrested a 43-year-old Australian-Iran dual citizen at the storage unit on Thursday. Police then searched a food importation business in Glendenning, and also some other units, houses and financial institutions.

Police believe they found 7.5 kilograms of ice, 36 kilograms of "black tar" heroin, 166 grams of brown heroin, $300,000 cash, jewellery and securities.

Investigators said they were also testing the contents of another tonne of fruit juice boxes.

Go to www.blacktownsun.com.au to see footage of the bust.