The alleged incident was witnessed by a number of children and teenagers on the bus, with many of the younger pupils left shaken and crying for the remainder of the journey.
Parents were outraged by the driver's actions and Go Bus terminated his employment.
The Otago Daily Times interviewed the parents of two children who saw the alleged incident but has chosen not to name them or identify the bus route involved, to protect the children who were on board.
The mother said her 9-year-old and 5-year-old children had reported what allegedly happened to her.
She said one mother had questioned the bus driver and another, the mother of a boy allegedly assaulted, had stepped on to the bus to ask what had happened.
She had contacted Go Bus and did not initially get a response.
"I found it incredibly difficult to get a contact number for them.
"I used their contact forum and said there was a, in my opinion, serious bus incident and I wanted to be called immediately."
