Officers are appealing for a man seen walking two dogs in the woods off Halton Moor Road, Leeds, who it is believed may be a witness to the assault reported to have taken place between 3.30pm and 4pm on February 22.
The victim has reported seeing a man walking two dogs in the woods around the time of the offence. He is described as white, of large build, wearing a khaki green top and brown or black bottoms.
A boy, aged 15, has voluntarily attended a police station and been interviewed in connection with the offence.
Det Insp Tanya Wilkins, of Leeds District Safeguarding Unit, said: “We would urge this man to come forward as he may be able to provide us with information which could help our ongoing enquiries in to this offence. Similarly, we are keen to hear from anyone else who was in the wooded area off Halton Moor Road around the time of this reported incident who has seen or heard anything that may be connected.
“Anyone with information is asked to call Leeds District Safeguarding Unit on 101.”