He said members of the public held the key to finding it.
Cairns said people at the scene would have seen the motorcycle, but no one had come forward with information so far.
"This is a tragedy that has happened to this young man, and police are trying to establish the events that led up to his death."
Cairns said it was too early to know how the man died or whether there was a gang element. He said police also did not know the make and model of the motorcycle he was riding.
The scene of a crash where a motorcyclist died near Murupara on Sunday. Photo / Stephen Parker
Meanwhile, Inspector Brendon Keenan, Rotorua's area prevention manager, is calling for the district's motorcyclists to put safety first.
He said two fatal motorcycle crashes near Rotorua, in the last week, were still being investigated and it was too early to comment on how or why they occurred, but he asked road users to pay attention and make safe decisions.
A man died following a motorcycle crash on Sunday.
"Every driver and rider should be in a position to react safely if someone makes a mistake in front of you. Err on the side of caution, even when you think you have the right of way. Being safe is more important than being right."
He said motorbikes could be difficult to see, so he asked drivers to look twice at intersections and before changing lanes.
"We also urge motorcyclists not to take risks. An unsafe manoeuvre or going too fast for the conditions could have tragic consequences. Also, bear in mind you may be in a blind spot when overtaking.
Rotorua's area prevention manager, Inspector Brendon Keenan. Photo / File
"We also encourage riders to look in to the Ride Forever courses that are available. These safety training courses are run throughout New Zealand and are a great benefit to any riders at any stage of their riding experience. Being familiar with your vehicle and knowing how to handle it properly could save your life."
The Murupara crash was one of two fatal motorcycle crashes in the region last week after a man died at Tauriko in Tauranga near the intersection of Sycamore Rise and Cambridge Rd at 4.30am on Sunday.
Eleven people were killed in road smashes in the Rotorua district alone last year.
It was a bad year for the entire Bay of Plenty in 2018, with 51 road deaths, compared with 47 in 2017 and 46 in 2016.
Anyone with information about the State Highway 38 crash is urged to contact Murupara police, Rotorua police or the anonymous Crimestoppers line on 0800 555 111.
