The cause of a scrub fire near Waldronville on Sunday has yet to be established.
Hundreds of people watched two helicopters with monsoon buckets and five fire appliances fight the raging vegetation fire which burned about 5ha of scrub next to the Otago Pistol Club's shooting range.
The fire was believed to have started in some tyres but the cause is yet to be determined.
Otago Rural Fire investigator Graeme Still could not give a precise cost of fighting the blaze at this stage, but said it could be in the thousands of dollars.
''We had two helicopters on site and numerous firefighters.''
Mr Still said the fire appeared to be suspicious and he was working to eliminate possible causes.
''It's probably started by human influence, to be fair, but it is a possibility it could have been started by a lightning strike.
''What we do is eliminate the possible causes - that's how we come to an answer.''
