Queenstown police have received a report of a spotlight being shone into the cockpit of a Queenstown-based helicopter on a night medivac mission.
Police said the incident, on Tuesday about 11pm, was in the area between Alexandra and Bannockburn.
It temporarily endangered the aircraft by limiting the pilot's ability to navigate using night vision goggles.
Senior sergeant John Fookes said shining lights or lasers at aircraft endangered those on board, and was a serious offence.
"In this area, any helicopters operating during the hours of darkness are on medivac or search and rescue missions. The endangering of the aircraft and occupants also jeopardises those for whom the mission is being carried out."
