A number of passengers had confirmed that seatbelts were being worn at the time of the crash.
One survivor, Mr Wang, who escaped the crash with minor injuries, said this trip was the first time he had ever been abroad, SkyKiwi reported.
He said in the immediate aftermath of the crash, fellow passengers could be heard crying "wounded and dead, tragic and tragic".
Wang rushed to assist other people who were trapped, however, there was little he could do without putting them in even more pain.
"Many seriously injured people were suppressed. I (tried to) pull them. The injured people shouted, 'don't pull!'," he said.
Wang's wife received more serious injuries in the crash and was still in hospital in Rotorua, SkyKiwi reported.
He estimated that it took emergency services around 20 minutes to arrive and praised the paramedics at the scene, as well as passing motorists who helped out.
Li Yang, a tourist from Sichuan province, was left uninjured in the crash but said her sister-in-law was in hospital with rib and scapula injuries, SkyKiwi reported.
She said she had been sitting in the fourth row of the bus when she felt it shake violently, before spinning off the road, where it rolled over.
She said passengers seated in the same row were all wearing seatbelts, but was not sure about others behind.
SkyKiwi reported that other passengers who were not seriously injured confirmed that they were wearing seatbelts too.
The passengers who were left uninjured in the crash were staying at a hotel in Rotorua.
They were meant to be in New Zealand for nine days, before travelling to Melbourne.
Many of the tourist's luggage was being temporarily held by police, while their visas were with the tour company.
Due to the lack of Chinese-speaking police officers in Rotorua, some passengers were being transferred to Auckland to take statements and verify identities.
There were 27 Chinese nationals on board the bus, SkyKiwi reported.
