The Cotswolds neighbourhood policing team said work by officers from a Neighbourhood Support Team led to a suspicious vehicle being stopped in Tetbury.
Class A drugs, cash and phones were seized from the two people inside, who were arrested on suspicion of possession of drugs with intent to supply.
The car was also seized.
A subsequent property search, also in Tetbury, resulted in the arrest of a third person and the seizure of evidence linking the suspects to the sale of drugs.
The suspects were being dealt with by officers from the local NST on Thursday evening.
The Cotswolds neighbourhood policing team said they would be seeking to remand them in custody for court in the morning.