Several members of the public have reported how a section of Silver Street, which is busy with bars, restaurants and takeaways, was cordoned off last night and into the early hours of this morning.
One person claimed a police officer was seen giving a man chest compressions at the scene.
A short video clip taken at the scene by a passerby appears to show police officers tending to a person on the ground.
South Yorkshire Police have not confirmed any details about the incident as yet.
We have contacted the force, and Yorkshire Ambulance Service, to ask for comment and are waiting for replies.