Police say it is disappointing an emergency flare set off in Te Anau appears to have been a hoax.
Senior Sergeant Peter Graham said the police received three calls from Te Anau residents on Saturday night after they saw a red flare drifting into the sky.
He said emergency services were immediately dispatched, including a helicopter with night vision capability and other vessels for a water search.
No boats were reported overdue and no-one was found to be in danger.
Mr Graham said volunteers put their own lives at risk to help others, and it was disappointing to think the flare could have been set off as a hoax.