He said local photographer Bryce McQuillan had suggested it was a striped skink and Dylan van Winkel from Bioresearches Group, one of New Zealand's leading reptile experts, confirmed it.
"We are hoping there is a little colony up there, that would be fantastic."
Although it took only two days to get the confirmation, Rotorua Canopy Tours wanted to check with the Department of Conservation it was in the skink's best interest before going public with the news, Mr Coker said.
That was because it was so rare and there was a lucrative trade to steal the species, he said.
Mr Coker said the skink looked like it was a mature adult and had apparently been quite happy to sit on the tree as the group took photos.
All the customers had been very excited, he said.
In the Rotorua region, only two of this rare lizard species had been found, both being about 20-30 years ago, he said.
Fewer than 150 striped skinks have been recorded in the wild.
The Department of Conservation has said this sighting is the most easterly one recorded.
Since there is so little known about the striped skink, there has not been an opportunity for scientists to properly study them.
Mr Coker said the biggest problem for New Zealand species today was invasive predators, and the sighting was more proof the pest control the company had been doing in the reserve was helping to create a safe home for native animals.
A portion of every Canopy Tour eco tour ticket fee is invested into the Rotorua Canopy Tours Forest Restoration Project.
