The police say thieves who stole fuel meant for a helicopter at Dusky Sound could have put lives at risk.
The police in Winton are investigating the theft of the jet fuel from two jerry cans on a barge in Luncheon Cove.
The fuel was replaced with water, which caused a helicopter to shut down on the barge after it was refuelled.
The police say the pilot and passengers would have been at substantial risk if the helicopter had stopped during flight.