Detectives are trying to trace a Good Samaritan who helped a teenage girl when a stranger grabbed her arm.
Police want to speak to the man in case he has information which could help with the inquiry.
At about 3.45pm yesterday, the 17-year-old was walking along Ray Street in Heanor when a car pulled up alongside her.
The driver reached out of the open window and grabbed her arm.
A passer-by then intervened and the driver let go and drove off.
The Good Samaritan made sure the young woman was alright before leaving.
The driver is described as black and in his 30s. He drove a new style blue Fiat Punto.
Anyone with information should call police on 101, quoting crime reference number 29760/15, or Crimestoppers on 0800 555 111.