Detectives investigating a sexual assault on board a train from Nottingham to Leeds are today releasing these images in connection.
At about 6:15pm on 5 February a woman was on board a train when a man sat next to her and sexually assaulted her.
Officers believe the man in the CCTV images may have information that could help their investigation.
Anyone who recognises the man in the CCTV, or has any other information, is asked to contact British Transport Police by texting 61016 or by calling 0800 40 50 40 quoting reference 742 of 5 February
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.