Police have seized a "large quantity" of what is believed to be cocaine from a car on the M5 near Bristol.
Officers stopped a VW Golf and found more than 1kg (2lbs) of white powder.
An Avon and Somerset Police spokesman said a man, 44, had been arrested on suspicion of possession with intent to supply a Class A drug.
"A further search of an address in Easton resulted in the seizure of imitation firearms, ammunition, cash and further white powder," he said.
"The vehicle and the white powder is currently being forensically examined," the force spokesman added.
The man remains in custody helping police with their inquiries.