Detectives in Essex are investigating reports that a woman was sexually assaulted in a garden as she walked home after a night out.
The victim was attacked in Station Road, Epping, in the early hours of Saturday.
She was wearing a black dress and did not have a coat, police said.
Anyone who saw a man and a woman in the area at about 0200 GMT should contact police. A 70-year-old man from south London has been arrested and bailed.