Authorities renewed their warning Tuesday for Louisianians to regularly check their credit card and bank statements after a fraudulent card-reading device was found hidden inside a Baton Rouge gas station pump Monday.

Mike Strain, secretary of the Louisiana Department of Agriculture and Forestry — the agency in charge of inspecting the state’s gas pumps — said whoever inserted the “skimming” gadget discovered at the Shell gas station at the corner of Tom Drive and Airline Highway must have used an original or duplicated key to unlock the computer interface. The culprit isn’t believed to be a gas station employee, he said.

As part of a recent blitz by the agency, similar devices were found in gas station pumps in Shreveport and in Jefferson Parish over the past two months, he said. The tools mark a trend away from older devices attached to the exterior of card readers, he said.

The U.S. Secret Service, which investigates money laundering, is a partner in the probes, Strain said. The skimmers can store large amounts of credit card numbers without the consumer’s knowledge, he said.

“We advise all consumers to check their credit cards statements and also their bank statements every month for suspicious activity,” Strain said.