Three men were being quizzed last night by detectives after a huge haul of credit cards and bank machines were discovered in raids.
Police found seven card reading machines and dozens of suspect plastic cards at a flat in Edgbaston.
The gear was seized along with mobile phones and paperwork by officers executing a search warrant.
It is believed that the equipment has been used to dupe banks and customers out of £1.8million through chip and pin fraud and card cloning scams.
A second swoop was carried out at a flat in the Pennfields area of Wolverhampton as part of an investigation into the alleged theft by fraud by use of card machine to the value of £400,000.