Manor Fields Park was sealed off yesterday morning following the discovery of a man’s body.
It remains under police guard this morning and South Yorkshire Police said the area is expected to remain cordoned off today and tomorrow.
Scenes of crime experts are examining the park looking for potential clues which could help police identify the killer.
In the only statement issued by the police so far, the force said: “A murder investigation has been launched after the body of a man was found.
“We were called at about 5.05am (yesterday) 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.”
Anyone who may have seen or heard any suspicious activity around the park between Wednesday night and Thursday morning or who may have CCTV footage which could be relevant should call 101 and quote incident number 122 of May 12.
Information can also be passed to Crimestoppers, anonymously, by calling 0800 555111.