Detectives are appealing for information after an alleged assault in a Clay Cross park.
A 33-year-old woman was in Sharley Park off Pilsley Road in the early hours of Tuesday.
She claims she was approached by a man who assaulted her.
During the incident, she bit him on the cheek.
The offender was black, about 6ft tall, of average build and clean shaven.
He was wearing a black coat and white shirt.
Detectives investigating the incident – which happened between 2am and 7am – want to hear from anyone who might have information.
In particular they want to trace a dog walker who was in the area and walked the victim home.
They also want to hear from anyone who recognises the description of the offender, who may now have bite marks to his cheek, and people who live near the park and have private CCTV.
If you live near the park and have private CCTV then officers would also like to speak to you.
Witnesses or anyone with information should call Derbyshire police on 101 or Crimestoppers on 0800 555 111.