Senator Lidia Thorpe interrupts royal reception for King Charles and ...

Independent senator Lidia Thorpe has interrupted a royal reception in Parliament House, yelling "you are not our king" and "this is not your land" to King Charles III, who sat a few metres away.

The monarch had recently finished addressing the reception when Senator Thorpe, who was wearing a fur cloak and had been standing quietly during the proceedings, stepped out into the aisle and began yelling.

"You committed genocide against our people. Give us our land back. Give us what you stole from us — our bones, our skulls, our babies, our people," she shouted towards the stage, where the king and queen were sat next to Prime Minister Anthony Albanese, before she was escorted out of the hall. 

"Give us a treaty, we want treaty," said Senator Thorpe, who is Gunnai, Gunditjmara and Djab Wurrung.

"F**k the colony."

Lidia Thorpe interrupted a royal reception at Parliament House, yelling at King Charles before being escorted out of the hall.  (AAP: Lukas Coch)

Charles and Camilla did not immediately react to the protest and mingled with the reception audience as they left the hall.

Earlier in the proceedings, Senator Thorpe had turned her back while a choir performed the Australian anthem for the royals. The independent senator is an outspoken advocate for Indigenous sovereignty and has long called for a treaty with First Nations peoples.

In a statement after the protest, she said she was attempting to hand the king a "notice of complicity in Aboriginal Genocide" according to the Statute of the International Criminal Court 1998.

The royals, along with Mr Albanese, his fiancee Jodie Haydon, Opposition Leader Peter Dutton, and his wife Kirilly, entered the hall to the sound of the didgeridoo and clapping sticks, while the Australian anthem was performed in both English and Ngunnawal.

"In my many visits to Australia, I have witnessed the courage and hope that have guided the nation's long and sometimes difficult journey towards reconciliation," the king said in his speech.

"Throughout my life, Australia's First Nations peoples have done me the great honour of sharing so generously their stories and cultures. 

"I can only say how much my own experience has been shaped and strengthened by such traditional wisdom."

Speaking before Charles, Mr Albanese said the respect that Australians felt towards the monarch "has been decades in the making". 

"It is a story that has seen so much change, what never changes is the truth stamped on every page of that story which is that your majesties are very welcome here," he said. 

Mr Dutton also acknowledged Charles's long relationship with Australia, noting it had been 58 years since "a somewhat shy boy" arrived on his first trip to Australia.

"Your presence here happily reminds Australians of all of the things that we love about Britain: Austin and Shakespeare, Churchill and Darwin, Queen and Dr Who, cricket and rugby, and of course, tea and pints," Mr Dutton said.

"But far more importantly, your presence here reminds us as Australians of our great British inheritance, of those features which have helped to forge a new nation."

Hundreds of people gathered outside Parliament House on Monday for a chance to meet the royals, lining the building's forecourt with small Australian flags in their hands. 

Earlier in the day the royals had met with the public at the Australian War Memorial, where a small group of protesters had also gathered.

Senator Thorpe was among the protesters and tussled briefly with police, the Daily Telegraph reported.

The Australian Monarchist League's national chairman, Philip Benwell, called for the senator to "step down with immediate effect" as a result of her protest at the reception. 

"Her childish demonstration has done nothing to diminish the gratitude and pride that millions of Australians have for our country, its history, its peoples and its sound system of governance," he said in a statement.