Five people have been arrested for supplying fake bus tickets in Brighton and Hove.
Police searched two properties in the city on Friday.
The fraudsters are potentially netting an income of tens of thousands of pounds.
Detectives have been working closely with Brighton and Hove Buses who are the victim of the counterfeiting operation.
Two men aged 21 and 24 and three women aged 20, 24 and 46, all from Brighton, were arrested on suspicion of fraud offences.
The 24-year-old man was also arrested on suspicion of possession of a controlled drug of Class B - cannabis.
Two were released under investigation, the other three remained in custody on Friday afternoon.