NSW RURAL Fire Service has confirmed a forensic investigation has been launched into the cause of a serious fire in Pottsville over Christmas.
Cudgen, Tweed Coast and Burringbar RFS Fire volunteer fire brigades were called in to battle the blaze about 2.30pm on December 25.
According to Tweed Coast club captain Mark Eglington, it was impossible to access the raging fire, which started in the centre of the wetland near the Black Rocks estate.
So a decision was made to create a buffer between the fire and the bordering 150 homes by back burning.
"We did have a lot of concerned residents because they had never seen anything like this before, which was pretty understandable," Mr Eglington said.
"To make it worse, it's a sensitive area for koalas and a few had concerns about the animals.
"We did manage to save four of the poor little buggers, who were very lucky to have been on the eastern side of the fire where we were doing the back bringing.
"There could've been more in the bush, but we had no access into it."
Back-burning operations continued into Boxing Day, when an extra four RFS brigades were called into Pottsville from southern New South Wales.
At lunchtime the next day the blaze died out.
It destroyed 130 hectares of vegetation, but not a single home was damaged, an outcome praised by Mr Eglington.
"This was the worst fire we have had in that piece of ground for over a decade," he said.
"At times we had up to 30-odd personnel on the ground in very hot temperatures between 30 and 33.
"The wind was strong from the north which caused headaches, but everything was saved."
"The people that we did get there, to leave their families on Christmas and Boxing Day and turn up did a really good job."
No fire permits were issued on Christmas day and an RFS investigation into the cause of the fire is expected to take anywhere from one day to a month to complete.
"An investigator will go on site and examine various aspects of the fire break, to determine the point of origin and there is a variety of forensic examinations that may take place," spokesperson Matt Sun said.
Team Koala representative David Norris said the group would visit the site over the next few days to look for koalas dead or alive.
The most recent scientific habitat study in the Tweed Shire, in 2011, estimated at least 35 of the native animals occupied the area affected by the fire.