Norwich — An autopsy of a man’s body found in the Shetucket River on Saturday evening was inconclusive, and his identity still is unknown, Norwich police said Sunday.

A caller reported seeing the man’s body at about 8:30 p.m. Saturday. The state Office of the Chief Medical Examiner performed an autopsy that did not have conclusive results, police said Sunday, and police still are working to identify him.

Norwich police, the medical examiner’s office and staff at the state’s Forensic Science Laboratory are investigating the man’s death and working to identify him, police said.

Police described the man as between 45 and 55 years old, about 6 feet tall, and weighing about 200 pounds. He has brown eyes, medium-length brown hair and a brown and grey beard. He was wearing tan cargo shorts and an olive-colored plaid button-down shirt.

Police asked anyone with information about the unidentified person to call Norwich police investigators at (860) 886-5561 ext. 6 or to call the department’s anonymous tip line at (860) 886-5561 ext. 4.