Police have arrested a 65-year-old man on suspicion of indecent assault.
The case came to light after a video taken by a pedestrian and circulating on social media purportedly showed a bus passenger touching a female passenger who was sitting in front of him on board a double-decker bus in Mong Kok.
Officers said the suspect had left Hong Kong briefly following the alleged indecent assault.
He was apprehended on Friday night at the Hong Kong-Zhuhai-Macao Bridge checkpoint when he returned to the city.
