Franklin County Sheriff Pat Melton said Wednesday that Kentucky State Police have opened a criminal investigation regarding a former employee, but he would not discuss specifics.

"I'll give you more when I can, but I can't right now," Melton said. "It's an open investigation right now, and I can't comment on it."

Melton confirmed the investigation after a Herald-Leader reporter asked about sheriff's Detective Matt Brown. Brown resigned effective Monday, Melton said, "to pursue a job in the jewelry business." Brown could not be reached Wednesday for comment.

The Kentucky State Police Drug Enforcement/Special Investigations Branch West is conducting the investigation, Melton said. Supervisors were not there Wednesday afternoon to comment. State police began the investigation last week at the request of the sheriff's office, Melton said.

Franklin County Judge-Executive Ted Collins said Wednesday that county government, which handles the payroll for all county employees, had received no official resignation letter from Brown.

Franklin County Fiscal Court is scheduled to meet at 6 p.m. Thursday and is scheduled to go behind closed doors to discuss personnel, property acquisition and litigation, Collins said. But Collins, a former Franklin County sheriff, said Brown is not a topic of the closed-door portion of the meeting.