A man has died after he was involved in a crash in the Bay of Plenty.

Police were called to the crash between a car and a bus State Highway 5/Ngongotaha Road, Rotorua, at 12.45pm on Sunday.

"The driver of the car was taken to Rotorua Hospital in a moderate condition before deteriorating and being transferred to Waikato Hospital later that day," says a police spokesperson.

"The man, 84-year-old Rudolf Jacabus Hoogenboom of Rotorua, passed away in hospital on July 31.

"Police extend our sympathies to his family and friends."

Nobody on the bus was injured in the crash.

The Police Serious Crash Unit is investigating.