Some mountain bikers have been issued written Department of Conservation warnings for illegally cutting a trail through a pristine forest on Tauranga's doorstep.
The track was discovered by volunteers helping to reintroduce kiwi and kokako into the Otanewainuku Forest.
Otanewainuku Kiwi Trust chairman Hans Pendergrast said the volunteers were checking predator bait lines when they discovered the freshly cut track alongside No 2 Rd.
"They were dismayed," he said.
The trust contacted DOC staff who discovered that kilometres of track had been cut through the forest, branching off from the popular walking track to the summit and Whataroa Falls.
It was known that mountain bikers had been using the main track despite a sign at the entrance indicating bikes were prohibited.
"I am really pleased that DOC has taken a firm stand on the cutting of cycle trails through the forest," Mr Pendergrast said.
Even although there was only a slight chance riders would have hit a kiwi, he said he supported keeping cyclists out of the forest during this phase of the recovery, particularly when toxic baits were being laid.
"We need another 10 years at least for all the kiwi and kokako programmes to become a lot more established."
DOC senior ranger for bio-diversity Brad Angus said staff made contact with some mountain bikers and made it clear that they were not allowed to cycle in the forest.
"We take a dim view of people going in a creating their own tracks ... it was quite a number of kilometres."
Mr Angus said the bikers received formal warnings and letters, although what they did was an offence under the Conservation Act.
"We are obviously concerned that someone would do this without requesting permission in such a pristine podocarp forest."
The most important consideration was the forest's ecology and minimising damage to vegetation.
He urged mountain bikers to check DOC's website to see which forests they were allowed in, such as Whirinaki. They were not allowed in the Kaimai Forest Park.
DOC intends to improve the signage at Otanewainuku to make it clear that mountain bikes were not permitted in the forest. It had been a symbol sign.
Bay of Plenty Conservation Board chairman Ken Raureti said the actions of the mountain bikers in the forest came to the board's attention at a hui Tuesday last week, but it did not have enough information to form a collective view.
He said tourism and New Zealand's growing population was increasing the pressure on forest parks. Part of the board's function was to enable greater use of the parks and reserves, but that went hand-in-hand with sustainable management.
''We want to encourage people to get out into the environment ... but some areas have a different status to others. They were so environmentally sensitive that they have to be managed differently.''
- 1325ha of virgin unlogged podocarp forest
- Mountain rises to 640m
- Home to endangered kiwi and kokako