A kayaker paddling the Tennessee River in north Alabama found a body in the water on Monday, and authorities said they opened an investigation into the death.

The remains of a white male who appeared to have been in the river a couple days were located near a landing located north of the unincorporated community of Valhermoso Springs, news outlets reported.

Morgan County Coroner Jeff Chunn said the cause of death wasn’t immediately evident, and no boaters had been reported missing in the area, which is located across the river south of Huntsville and east of Decatur.

A person in a kayak spotted the body and contacted authorities, who used a boat to retrieve the remains.

“This is an active death investigation,” said Mike Swafford, a spokesman for the Morgan County Sheriff’s Office.