The driver of the Nissan vehicle involved in the head-on crash on the Kaimai Ranges that killed nine-year-old Katikati girl Jasnoor Kaur has died.

Police confirmed the 55-year-old Mount Maunganui man passed away in Tauranga Hospital overnight.

The driver of a Nissan vehicle has died in Tauranga Hospital early this morning.

The man was taken to hospital in a serious condition following the crash on Thursday, May 29 and remained in the intensive care unit where he passed away this morning.

Jasnoor was the rear seat passenger of a blue Subaru and died at the scene of the crash on State Highway 29, near the summit of the Kaimai Ranges.

Western Bay of Plenty road policing manager Senior Sergeant Ian Campion says police are still investigating the crash, but early indications are that the man's Nissan vehicle travelling west towards Matamata crossed the centreline on a moderate left-hand bend crashing with the Subaru Legacy.

A third vehicle, a Honda Civic, travelling behind the Subaru towards Tauranga crashed with the other two vehicles.

Four others in the Subaru, including Jasnoor's 12-year-old brother and a five-year-old boy were taken by St John Ambulance to Waikato Hospital.

The 12-year-old was transferred to Starship Hospital in the weekend where he is listed in a critical, but stable condition.

A five-year-old remains in Waikato Hospital's intensive care unit.

A 79-year-old Tauranga woman was also taken to Tauranga Hospital following the crash and remains in a serious condition.