Five people have been arrested on suspicion of drug and money laundering offences following a series of raids on houses in south Bristol.
More than 100 police officers took part in a push to target what the force describes as "a major crime family".
Eleven properties in the Knowle West area, and one in Dundry, were raided and £10,000 in cash was found at one address.
Cannabis production was found at three houses and a harvested crop was seized.
Avon and Somerset Police drew on officers from forces throughout the West Country in the raids, part of the Operation Zephyr initiative against organised crime.
The raids took place at Bridgwater Road in Dundry and Illminster Avenue, Kenmare Road, Marksbury Road, Timsbury Walk, Timsbury Road, Daventry Road, Wedmore Vale and St John's Lane in Knowle West.
The cash was found in the Timsbury Walk property.
A 30-year-old woman was arrested on suspicion of possessing a Class A drug with intent to supply, a 44-year-old woman was held on suspicion of production of cannabis and a 23-year-old woman was arrested on suspicion of handling stolen goods.
In addition, a 50-year-old woman and a 28-year-old man were arrested on suspicion of money laundering. All remain in police custody awaiting interview.
Police say all those arrested were related.
Mobile phones, police jackets, bicycles and other suspected stolen goods were also discovered in the operation, as was a small quantity of cocaine.
Police say the total value of property owned by the family was £2.5m.
Chief Insp Steve Kendall said: "In time we will be looking to seize assets under the Proceeds of Crime Acts."