Three passengers of the bus, who were children, sustained minor injuries during the collision.
At around 4.35pm on Monday (26/2) a white, blue and orange double decker school bus was involved in a collision with a silver Mercedes CLK convertible on the A421 (H8 Standing Way) near Furzton.
Officers from the Joint Operations Unit for Roads Policing are investigating the circumstances of the collision.
Investigating officer PC Ian Stevens, based at Milton Keynes police station, said: “I would like to hear from anyone who witnessed the collision or who saw either vehicle being driven beforehand.
“We are particularly keen to speak the driver of a car, which was possibly a Peugeot, which was travelling directly behind the bus at the time of the collision.
“If you have any information which could assist our enquiries, please make contact with police.”
Anyone with any information about the collision should contact PC Stevens via the 24-hour Thames Valley Police enquiry centre on 101 quoting the reference URN 972 26/2 or Crimestoppers anonymously on 0800 555 111.