A woman was raped by a stranger who shared a taxi with her and her boyfriend after a night out in Leeds.
The 19-year-old and her partner had been in Leeds city centre last Wednesday before getting in a cab in the early hours to return to his home in Headingley.
Another man got in with them and joined them back at the property.
The woman later contacted police alleging she had been assaulted by the man, who then escaped.
Detectives have now released a CCTV image of a man they want to trace.
Det Supt Nick Wallen, of West Yorkshire Police Protective Services, said: “I would ask that anyone who knows his identity or who has any information that could assist in tracing him contact us immediately.”
Call 101 or Crimestoppers, anonymously, on 0800 555 111.