Two helicopters battling a large blaze near Omarama this afternoon were grounded after a drone was seen nearby.
A person close to the operation said the helicopters were grounded for about 20 minutes and police had been notified.
Neither the drone nor its operator had been found, they said.
The helicopters were deployed to help battle the large blaze in Broken Hut Rd, south of Omarama, which sparked about noon.
Fire and Emergency New Zealand shift manager Andrew Norris said crews from Omarama, Twizel and Kurow were struggling to contain the blaze, which had destroyed a hay barn and spread to surrounding trees.
About 20 firefighters were at the scene, he said.
Fire crews were alerted to the blaze about 12.20pm.