On Wednesday, a police spokesperson said the boy had since been discharged.
Hughes said Ritchies had carried out an “immediate safety inspection” on all buses equipped with the same emergency exit.
An Auckland Transport spokesperson said the bus involved in the incident had been removed from service for inspection.
Other buses of the same make were checked to ensure they were secure.
Ritchies declined to comment while the investigation into the incident was underway.
A police spokesperson said the bus was travelling at a low speed when the boy fell out of the exit.
“The child suffered moderate to serious injuries and was transported to hospital.
“The incident is currently being investigated by police, WorkSafe and the bus company involved.”
A WorkSafe spokesperson confirmed it had been alerted to the incident, but police were the lead agency.
“If police identify any potential health and safety failings as part of their inquiries, they can be referred to WorkSafe.”
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