The Aboriginal Tent Embassy said it did not condone the actions of protestors which led to a fire burning the doors of Old Parliament House in Canberra.
Police said the fire, which broke out at around 11.45am, was set by protestors and quickly extinguished.
The front of the 1927 building was damaged, with the ornate front doors completely destroyed.
Protesters have been outside Old Parliament House for more than a week and began a traditional smoking ceremony on Thursday.
Protesters stand in front of the burned out entrance doors to Old Parliament House. Source: AAP
In a statement, the Aboriginal Tent Embassy said: "The actions of such protestors conducting a "Smoking Ceremony" was done so without the knowledge, consent or mandate of the Embassy's council or Traditional Owners responsible for regulation of the Aboriginal Tent Embassy.
"Although we support the concept of nonviolent direct action, we do not condone the destruction of public and private property."
An ACT Policing spokesperson an investigation had begun, adding: "There has been ongoing protest activity at the front of Old Parliament House throughout the past fortnight."
Fire fighters are seen entering the fire damaged entrance to Old Parliament House in Canberra, Thursday, December 30, 2021. Source: AAP
Prime Minister Scott Morrison, speaking at a press conference, said he was "disgusted and appalled" by the fire.
He added: "I just think it's appalling and I think it's disgraceful, and I think that the authorities should act swiftly and in accordance with the law and people should face the consequences for their actions.
"I'm disgusted and appalled by their behaviour that would see Australians come and set fire to such a symbol of democracy in this country."
Deputy Prime Minister Barnaby Joyce said if the fire was deliberately lit it would be "an absolute disgrace".
"This is the Parliament that for so long underpinned the freedoms we have as a democracy and made the decisions that formed us as a nation, fighting for the increase of rights and corrections to our colonial past," Mr Joyce wrote on Facebook.
"If someone is trying to make a statement then it is a very bad one that will be received with overwhelming disgust."
Opposition Leader Anthony Albanese said it was a "very historic building".
A view of fire damaged entrance doors to Old Parliament House in Canberra. Source: AAP
"I had the great honour of working for Tom Uren in that building. It's used by school groups, it's used for educational purposes as well as for functions," he said.
"It's an important building and I just hope that there is only minimal damage."
Former Nationals leader Michael McCormack said there should be “swift and severe” repercussions for those responsible.
Protesters stood in front of a line of Police officers guarding Old Parliament House. Source: AAP
“How disgraceful. An outrageous attack on our democracy, our history, our sovereignty. This modern penchant for tearing down our past serves no purpose,” he said on Twitter.
Resources Minister Keith Pitt also weighed in on Twitter, commenting: "No matter what your cause, setting old Parliament House on fire and endangering all those inside is not the answer ... Hope everyone is safe."
The building ceased being used as the home for parliament in 1988 and is now home to the Museum of Australian Democracy.
