Fire crews have battled two scrub fires in the area in as many weeks, with the one on Thursday burning an area of 100m by 300m.
Otago Rural Fire Authority fire investigator Jamie Cowan said today that a pile of ashes from what appeared to be a barbecue were found in the area.
The ash piles were not related to either fire and both were still being investigated.
It appeared the ashes were dumped under trees and bushes without being watered down - a major concern for fire authorities, Mr Cowan said.
"There are a huge number of fires both house and vegetation fires each year caused by ash being dumped... In both these cases the ashes were dumped without being wet down which is an absolute sitter for causing a fire.''
Mr Cowan said he was unsure exactly what sort of device the ash had come from but was concerned there could be a new type of cooking barbecue being used by campers.
"I saw one in a camping area I was in a couple of weeks ago and I didn't think too much of it then I saw another couple yesterday near the site of the fire.
"It may well be a small portable barbecue or it may be a cool new device campers are using that I don't know about.''
If it was a new type of cooking device Mr Cowan said he wanted to know more about it so he could run a risk assessment on it.
