A man exposed himself in front of passengers at around 5pm on the 14th of April.
Detectives are urging anyone who recognises the man in the CCV images to come forward.
Anyone who recognises the man is asked to contact British Transport Police by texting 61016 or by calling 0800 40 50 40, quoting reference 451 of 14 April.
Information can also be given anonymously to Crimestoppers on 0800 555 111.
