FREELAND, Mich. (AP) — Authorities say cellphones and marijuana arrived with a food shipment to a Michigan prison.

Michigan Department of Corrections spokesman Chris Gautz tells the Detroit Free Press that inspectors at Saginaw Correctional Facility in Freeland, about 95 miles northwest of Detroit, found the contraband Monday and turned the case over to state police to investigate.

State police say it’s too soon to release details. Lt. David Kaiser tells WNEM-TV that such finds are made “from time to time.”

Gautz says the food delivery vendor, Sun Valley Foods, is cooperating.

The Associated Press sent an email seeking comment from a representative of Sun Valley Foods on Friday morning.

Gautz says the Corrections Department is conducting an internal investigation to determine whether inmates who work in the kitchen were anticipating the illegal delivery.