Four men, who described themselves as “bushfire hunters”, have been cleared of responsibility in starting the blaze that threatened hundreds of homes on the weekend.
The men, aged 18 to 21, went to Liverpool police station on Monday after a video, posted on Snapchat, was widely publicised.
A police spokesman said the video was taken in the Barden Ridge area.
Acting Superintendent Paul Albury said the men went to the area three days after the bushfire started to take the video.
“They were very apologetic,” Mr Albury told 9 News.
“The young men come from decent families, who have been mortified by the interest around their sons and the embarrassment caused to their families.”
On Facebook, the men boasted of being bushfire hunters.
”We weren’t laughing at the fire. We were laughing at each other’s jokes,” one of the men told 9 News.
Another denied being embarrassed.
Inquiries continue into the deliberately-lit fire, with police still appealing for anyone with information to come forward.
The fire has now burned through 3800 hectares and after three days burning out of control, has been contained.
Firefighters will remain onsite over the coming days to continue mop up and patrol operations.
The initial plea from police
Police investigating the deliberately-lit fire that has torn through more than 3200 hectares of bushland on the south-western outskirts of Sydney want to speak with a group of men seen in a video on social media.
Around 9.30am on Tuesday, Bankstown police received the video footage after it was posted to Snapchat, showing a group of men cavorting around a grassfire as flames began to engulf nearby trees.
It's believed the video, which shows the men laughing and cracking jokes as the small fire around them grows, may have been shot in Heathcote – one of the areas the weekend bushfire burnt through.
One of the men is heard asking: "Do you know how fast fire burns?"
And later, with a line of flames along the nearby grass, "National Geographic over here".
The video was passed on to Strike Force Carpi, which is investigating how the suspicious bushfire, burning out of control since Saturday, was started.
There is no suggestion that the men in the video are responsible for starting the fire. However, police are urging the men – along with any other witnesses – to come forward.
The fire is still burning within the Holsworthy Range and around Barden Ridge, with more than 200 firefighters continuing backburning operations across the fireground to establish containment lines.
Fire investigators have been working alongside NSW Police's Strike Force Carpi to determine the cause of the fire, but according to the NSW Rural Fire Service Commissioner Shane Fitzsimmons, it was "most likely deliberately lit."
A furious Mr Fitzsimmons described the actions of bushfire arsonists as "sickening and reprehensible" on Monday.
"How dare anyone in society think that they can deliberately light a fire ... and, in turn, put so many members of the community – be they people in homes or businesses or indeed the travelling public – at risk."
Access to Sandy Point, Pleasure Point and Voyager Point is still for residents only with photo identification via police escort.
After viewing the Snapchat video footage on Tuesday, Mr Fitzsimmons said it was "concerning to say the least".
He said the actions of the men in the video were at best "a gross act of stupidity." But, he added, "clearly it could be a whole lot more."
Miraculously, no lives or homes have been lost in the bushfire as it skirted, and singed, Sydney's southern suburbs including Voyager Point, Pleasure Point, Sandy Point, Alfords Point, Barden Ridge, Illawong, Menai and Bangor.
The fire was downgraded to 'advice' level on Monday, with Heathcote Road and New Illawarra Road able to reopen fully on Monday evening, but residents are urged to remain vigilant "as there is still a lot of fire around", Mr Fitzsimmons said.