A ticket inspector was attacked by three bus passengers and beaten up after asking to check their tickets.
Police have released images of people they want to speak to in connection with the assault which happened on route 199 on Grove Street in Lewisham.
The 34-year-old victim, a TfL Revenue Protection Inspector (RPI), was attacked by two men and a woman at about 6pm on Friday, January 3.
He was punched several times, sustaining facial injuries.
The first suspect has been described as a white male, aged between 20 to 30-years-old, large build, with very short dark hair and receding hair line and was wearing glasses.
The second suspect is described as a white female, aged 20 to 30-years-old, large build with shoulder length hair.
And another suspect has been described as a white male, aged 20 to 30-years-old, of medium build with short hair.
Officers from the joint Transport for London and Metropolitan Police Service Safer Transport Command Workplace Violence Unit have launched the appeal for information.
Call 0203 054 4569 or Crimestoppers anonymously on 0800 555 111 with information.