Rogue tourists are being warned to heed local advice about weather conditions on the Tongariro Alpine Crossing.
The umbrella group of official guides working on the famous day walk says their efforts to keep visitors safe are being undermined by a small number of individuals who ignore expert advice and put their lives at risk.
"We are very pleased with the contribution the Tongariro Alpine Crossing Transport and Guide concessionaires group (TACTAG) is making to alpine safety," said its chairman Stewart Barclay.
"However, some visitors are not heeding the advice of our members and other experts and are attempting the Crossing when the weather is unsuitable and without appropriate clothing and equipment."
"The Crossing can be an extreme environment in wintertime with snow and ice and rapidly changing weather conditions."
Police commander for the Ruapehu area, Inspector Steve Mastrovich, said a group of about 10 international visitors was recently advised by tourism experts in Taupo and Turangi that they weren't equipped or experienced enough to do the crossing but carried on anyway.
"They drove to the track by private vehicle where they ignored further warnings by two TACTAG members not to proceed.
"They became lost and were very lucky to be rescued without mishap. These visitors need to understand that Search & Rescue isn't a back-up to poor decision making, and they need to listen to the advice of the people who have local knowledge."
Tongariro Alpine Crossing is recognised as one of the best day walks in the world and a lot of work has been done by TACTAG since its formation in 2007 to strengthen protocols that guide operators on weather conditions and the minimum equipment for trampers.
At TACTAG's latest meeting, the Department of Conservation said in the future it would require operators holding concessions to provide guiding and transport services for the crossing to be TACTAG members and abide by its protocols.