Firefighters prevented the blaze, on November 7, from spreading to housing in the area.
Doc Wakatipu Rural Fire Officer Jamie Cowan said the group of youths, reportedly a local church group, would likely be held responsible for the fire and be charged with the bill incurred by the New Zealand Fire Service, the helicopter used and Doc.
"At this stage the people who lit the fireworks are likely to pay for the extent of the damage, but that is still under investigation," Mr Cowan said yesterday.
Firefighters were called to the Basket of Dreams area at the top of Queenstown Hill at 10pm on November 7, but because there was no road access, they had to run 1km uphill to get to the reserve.
A helicopter equipped with night vision equipment was also called to assess the area, while officers made sure the fire, which burnt about 0.5ha, did not spread to nearby houses.
It took more than four hours to bring the blaze under control.
At the time, Mr Cowan said it was extremely lucky it had not spread further.
