After learning on March 25 that certain customers had experienced unauthorized charges to their credit cards in November and December 2014, Vermont and New York-based Healthy Living Market and Café is conducting a data breach investigation.

Details are sparse, but Healthy Living is working with federal law enforcement and has also engaged third-party data security experts, according to a notification posted to the website on Friday.

“Our investigation is ongoing and at this point, we do not believe that our IT systems were the source of a data security breach,” the notification stated. “We believe that any breach of our data security would have been limited to the unauthorized access of customer names and credit card numbers.”

Customers are being notified, but because a breach has yet to be confirmed, Healthy Living has not determined what remedial steps are needed.