The decomposed body of a man was found by bird watchers washed up near a nature reserve on the Humber river.
The body was discovered by the three men at 2.30pm on Sunday in Paull, near Hull, and police and the coastguard were called to the scene.
Detective Inspector Paul Welton, from Humberside Police's marine search unit, said it appeared the body had been brought in to land on the high tide.
He said: "At this stage all we can ascertain is the body is a man. Due to the condition of the body, I am unable to confirm anything else.
"There is nothing to suggest the death of the man is suspicious, I am treating the death as unexplained.
"The man appears to be fully dressed and had a set of keys and a phone on him. I am now pursuing a number of lines of enquiries to identify the man discovered today.
"We have also visited all families who have missing loved ones, who are believed to have gone into the Humber. The people who discovered the man have also been reassured and offered support."
PA
