A group of football supporters travelling on the 6.15pm service from Plymouth to Paddington on Sunday 31 October were reported to be singing homophobic chants, making other passengers feel uncomfortable.
Officers believe the men in these images may have information that could help their investigation.
If you recognise them or have any information, please contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 2100082301.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.
