Questions have been raised about the future of a warning system that alerts people on Mt Ruapehu to impending eruptions.
Skifield operator Ruapehu Alpine Lifts usually pays 80 per cent of the cost of the $62,000 detection system under an arrangement with the Department of Conservation, but it hasn't been meeting payments.
The early warning system alerts skiers and others on Mt Ruapehu that they may have just minutes to get out of the way of potentially devastating lahars streaming through the mountain's valleys.
It's one of five systems for warning of the danger and Department of Conservation scientific advisor Harry Keyes said it's probably the most important.
"When Ruapehu erupts the mountain often sends volcanic floods, or lahars, down valleys," he said.
"If a person's in that valley they're at significant risk."
Negotiations between DoC and Ruapehu Alpine Lifts are ongoing, but Dr Keyes said they would find a way to fund the detection system - one way or another.
"The day the eruption detection system is needed it'll be cheap. We're not playing Russian roulette here, we are dealing with an active volcano and we've all got a collective responsibility to ensure the eruption detection system is as good as it can be."
Ruapehu Alpine Lifts could not be reached for comment.