UPDATE AT 1.50pm - murder investigation launched
An official statement read: "We were called at about 5.05am by a member of the public to report that they had found the body of a man while walking in Manor Fields Park, off City Road.
"He is yet to be identified, and officers are working to establish who he is.
"At this time, a police cordon remains at the site. The whole park remains closed off, and people are asked to please avoid the area while officers continue their work. We appreciate your patience while the investigation work continues.
A man's body was found in Manor Fields Park, off City Road to the east of the city centre, just after 5am.
No further details have yet been released and investigations are ongoing.
SYP said: "Good morning South Yorkshire. There is currently a police cordon in place around Manor Fields Park off City Road in Sheffield this morning. Please avoid the area while officers carry out their work. Thank you."
Further updates are expected later today.
The park was once part of the Great Sheffield Deer Park, a large hunting estate, before the land was used for mining in the 19th century. During World War Two, the area was turned into 'Dig for Victory' allotments for food growing. It fell into decline until the 1990s, when a major restoration of the wasteland began and it is now an important wildlife habitat.
The site is owned by Sheffield City Council and managed by the social enterprise Green Estate.