Eight people were arrested and drugs with a street value of more than £320,000 were seized after a property was raided in South Gloucestershire.
About 14kg of amphetamine and 37kg of cannabis, plus cash, was found during the raid in Marshfield.
Further searches have been carried out across Bristol, London and Surrey.
Specialist search teams including trained drug dogs were used to help locate the drugs and the money, said Avon and Somerset Police.
Two people were later charged with possession with intent to supply and six others were bailed.