Police in Knoxville are investigating the discovery of man's body in a pickup truck.

The Knoxville News Sentinel reported the body was discovered Sunday afternoon on the floor of the truck, which was behind Fountain City Lake.

Police said the man was 43 years old.

A family eating lunch at the lake noticed the man on the floor of the vehicle and flagged down a passing Knoxville Fire Department truck.

The man's name was withheld while his family members were told. His body was taken to the Regional Forensic Center for autopsy.