Human remains have been found in the River Severn in Shropshire, police say.
Officers were first alerted shortly before 21:15 BST on Saturday by a member of the public who spotted what they believed to be remains in water at Cressage, between Shrewsbury and Much Wenlock.
It is thought they had been in the water for a significant amount of time, said West Mercia Police.
The death is being treated as unexplained, it said.
Police officers and Shropshire Fire and Rescue Service attended the scene.
Det Ch Insp John Weaver said the priority was to identify the deceased.
"The remains are being forensically examined and the results will determine the next steps in our investigation.
"This could be a lengthy process but we will update the public in due course," he added.
There will continue to be a police presence at the scene while searches are carried out, the force said.