Detectives are still trying to establish what exactly happened to a woman believed to have been sexually assaulted in a Sheffield park.
The 21-year-old was walking home when she was ended up unconscious in Weston Park, with detectives treating her as a suspected sex attack victim.
It is believed she was unconscious for around two minutes.
Yorkshire Ambulance Service reported the incident to South Yorkshire Police.
Forensic enquiries have been carried out, CCTV footage has been examined and people in the area at the time have been interviewed.
A South Yorkshire Police spokeswoman said: "Enquiries remain ongoing establish exactly what happened while the woman was unconscious and to determine a satisfactory conclusion."