A man sustained head injuries in what is believed to be an attack in the street.
Passers by rang an ambulance after finding the 37-year-old injured in Main Street, Maltby, at 3am on Saturday, June 24.
The man is recovering in hospital but his injuries are not thought to be life-threatening.
Police believe he may have been assaulted.
Anyone with information should call 101 and quote incident number 310 of 24 June or Crimestoppers on 0800 555 111.