DANVERS, Mass. (WPRI) — A New Hampshire man accused of operating under the influence of drugs early Saturday morning was found dead in his cell just hours later.

Massachusetts State Police said the 49-year-old from Fremont was stopped on Route 99 in Saugus around 2:30 a.m.

Once booked at the barracks the man was placed into a cell.

Police say regular face-to-face checks were performed every 30 minutes, but at 11:30 a.m. the man was found to be unresponsive. Danvers EMS responded and performed emergency first aid.

The prisoner was pronounced dead at the barracks and was transported to the Office of the Chief Medical Examiner.

The death is currently under investigation by the Essex County District Attorney’s Office.