At around 10.10pm on the night of Friday 28 February 2014, an altercation took place in the doorway of the bus before it departed from Harrogate bus station.
A man was heard shouting and behaving in an aggressive manner before physically removing a woman from the bus.
Police are appealing for any passengers or anyone in the bus station at the time who witnessed the incident, to contact them.
If you wish to remain anonymous, you can pass information to Crimestoppers on 0800 555 111.
Please quote reference 12140038442 when passing on information about this incident.