The FBI and US secret services have reportedly been called in to investigate a series of sophisticated “skimmer” devices planted inside petrol pumps in Pennsylvania.
Two of the devices were found at a petrol station in Schuylkill County allowing the perpetrators to steal PIN numbers from cards without any visible sign the pump had been tampered with.
Police said the devices were unlike anything they had seen before.
"I wouldn't have even been aware that this device was placed on the pump," St. Clair Police Chief William Dempsey told WNEP.
"Typically a skimmer would be placed on the outside of a gas pump or the outside of an ATM machine.
"Customer knowledge or customer awareness would not play a role in this.”
Marina Terwilliger is one of 40 victims that have come forward, including four of her coworkers.
"I feel panic. I feel violated because you know someone has your information and you don't know how far they'll get away with it," she said.
Police believe the perpetrators may have used a master key to open the pump, before replacing the cable with one which had an information storage device attached.
CACL Federal Credit Union, where some of the victims bank, warned customers to be vigilant.
"Vigilance, vigilance on your own bank account. We suggest for people to look at their accounts every single day," said CACL COO Francesco Mercuri.