A group of white supremacists are being investigated for staging a rally at a sacred Indigenous site.
Wollumbin Mountain, formerly known as Mount Warning, is off-limits to the public due to its significance for the local Bundjalung people.
Images posted on social media showed 13 balaclava-clad members at the top of the mountain in northern NSW holding a banner that read: "Mt Warning for the white man."
The group were members of the neo-Nazi National Socialist Network from Queensland who travelled to Wollumbin during a weekend in late October, according to a post on X.
NSW Police on Tuesday said officers had not been called to the site over the past two weekends to respond to protests, with investigators working with National Parks and Wildlife Service staff to look into the reported breach.
Environment Minister Penny Sharpe said any attempt to spread hate would be taken extremely seriously.
"This behaviour is utterly disgusting and I condemn those involved," she said in a statement.
"To these far-right extremists and neo-Nazis who are reportedly from Queensland. You and your vile demonstration are not welcome in NSW."
She said the behaviour was not acceptable anywhere, whether it be at sacred sites or on Sydney streets.
Wollumbin Mountain was declared an Aboriginal place at elevations above 600m under the former coalition state government in 2014.
The trail leading to the summit has been closed since COVID-19 restrictions were introduced in March 2020.
A local place management plan noted the mountain was a place of "the highest significance to the Bundjalung people", but public access to the peak had resulted in vandalism, graffiti, rubbish and other disturbance of the site.
Penalties apply for those who defy the ban, but several people have since climbed the mountain in protest.
NSW Libertarian MP John Ruddick in August posted a video of himself at the summit, saying he was part of a group of about 20 people who accessed the trail at the time.
Decisions about the future of the summit track would be made by national parks staff in accordance with the wishes of Aboriginal custodians, according to the service's website.