Police are appealing for a witness who discovered the body of a man in Long Eaton to come forward.
Officers said: "We are trying to trace a dog walker who found a man’s body in West Park, Long Eaton, in December.
"The man found the body at around 8am on Wednesday, December 21 and approached a woman who was walking by, asking her to call an ambulance.
"We have the woman’s details but the man had left the scene when emergency services arrived and we are trying to identify him on behalf of the coroner."
The circumstances of the death are said to be not suspicious.
Witnesses or anyone with information should call PC Rob Stapleton on 101, quoting reference 16000425638.
Alternatively, send him a message online by visiting the Contact Us section of the website www.derbyshire.police.uk/Contact-Us.
You can also call Crimestoppers on 0800 555 111.