Police are appealing for anyone who saw a 14-year-old girl the night she was assaulted in or around Ilkeston Market Place.
The girl – who has distinctive purple hair – was attacked between 4am and 7am on Saturday August 17, officers said.
She is believed to have been seen talking to three young men near the bus stop in Wharnecliffe Road, outside the Co-op.
One youth was described as white, about 17 years old, 5ft 7ins tall with brown hair and average build.
He had a Nottingham accent and wore an Adidas t-shirt, grey shoes and tracksuit bottoms. One ear was pierced with a yellow smiley face and he wore a chunky ring with a picture of a dragon.
A second youth had bleached blonde hair, shaved at the sides. He was skinny, about 16 years old and 5ft 5ins tall.
The third was older, maybe 20, and had chocolate brown hair, wearing blue tracksuit bottoms and white shoes. He was bigger than average build.
As well as the purple dyed hair, the victim is white, five feet tall and was wearing striped, coloured jeans and a hoody.
A police spokesman said: “Anyone who was in the area at the time, who saw any of these people or who recognises the descriptions of the youths should call police on 101.”