Minnesota Department of Corrections officials are investigating after a 22-year-old inmate was found unresponsive in his cell early Saturday and died at the scene.

Corrections officers at the Stillwater prison found the man about 3:30 a.m. and attempted life-saving efforts. The man, whose name has not been released, died about 20 minutes later, according to a statement from corrections officials.

While the cause of death was not immediately known, preliminary information indicated the victim may have used synthetic drugs, the statement said.

Foul play was not suspected, the statement continued.

"On behalf of the Minnesota Department of Corrections, I want to extend condolences to the young man's family," Commissioner Paul Schnell said. "If this death is determined to be drug-related, we will make every effort to determine who introduced and provided the substance for the purpose of pursuing prosecution to the fullest extent of the law."

Minnesota's prison system, along with those across the nation, is experiencing challenges related to synthetic controlled substances. Often the drugs are infused into paper that enters facilities through the mail. As a result of Saturday's incident, Stillwater prison personnel will photocopy all incoming mail except legal mail due to attorney-client privilege, the Department of Corrections said.

The unit where the man died remained on "lockup status" until further notice, the statement said.