Thames Valley Police has now released CCTV images of a man who may have information following a sexual assault in Banbury.
The incident occurred on May 17 on a bus travelling through Lower Cherwell Street and Bridge Street between 11.40am and 12pm.
The victim, a woman in her sixties, was sexually assaulted while on the B5 Stagecoach bus by a male passenger.
While the victim was sitting on the bus, the offender moved to sit next to her and pressed himself against her.
When the bus arrived in the town centre, the victim attempted to leave the vehicle and was again touched inappropriately by the offender.
Investigating officer PC Lucy McDonagh based at Banbury police station, said: “We are appealing for the man in these CCTV images to come forward because it is possible that he could have information vital to our investigation into this incident.
“If you are this man, recognise him, or have any information about the incident, please call the 24 hour police enquiry centre on 101.”
Or witnesses can call Crimestoppers anonymously on 0800 555 111.