The LSU hospital system has notified 416 patients that their checking account numbers and other personal information has been stolen and may have been used to make counterfeit checks.
Spokesman Marvin McGraw says the information was found in the home of a former employee arrested in November.
He says the LSU Health Care Services Division began notifying patients in November, after learning about the thefts from state police.
A New Orleans man has been arrested on fraud and identity theft charges for allegedly engaging in a scheme to defraud the PayPal online payments service.
Federal prosecutors said Friday's arrest of 28-year-old Giray Biyikioglu, a Turkish national who lives in New Orleans, follows a Secret Service probe.
Prosecutors said Biyikioglu illegally used somebody else's identity and conducted transactions of up to $190,000 as part of his alleged scheme to defraud.
No additional details about the case were immediately disclosed.