A woman was sexually assaulted in the early hours of New Year's Day in Norwich.
She was walking along Unthank Road, close to Beechbank, about quarter 4.15am when she was approached by a man.
He left when a group of people were dropped off by a taxi nearby.
Officers are appealing for anyone who may have witnessed the incident.
They would particularly like to trace the driver of the taxi who was in the area at the time.