Police say the body was reported to them at six this morning.
It was found near Palm and Nees Avenues by a man that spotted it just behind Spano Park on a walkway leading to the river.
"We arrived, found the body he was just on the other side of the fence, not very far towards the river. Maybe 20 feet into the trail, slumped over. Really can't tell," said Fresno Police Department Lt. Joe Gomez.
Homicide investigators are now working to identify the man and how he died.
Officials are not yet saying if he suffered any sort of trauma. Police believe the man may have been homeless since they say homeless people frequent the park -- and go down to the river at night.
Last week a homeless man was found dead near an off-ramp at Highway 41 and Herndon Avenue. That death was determined to be from natural causes.