Indigenous senator Lidia Thorpe shouted anti-colonial slogans at King Charles during his visit to the Australian parliament on Monday, shocking assembled lawmakers and other dignitaries.

"Give us our land back! Give us what you stole from us!" Thorpe screamed in an almost minute-long diatribe, after the 75-year-old king's speech.

"This is not your land, you are not my king," the independent lawmaker said, decrying what she described as a "genocide" of Indigenous Australians by European settlers.

Australia was a British colony for more than 100 years, during which time thousands of Aboriginal Australians were killed and entire communities displaced.

The country gained de facto independence in 1901, but has never become a fully fledged republic. King Charles is the current head of state.

Charles is on a nine-day jaunt through Australia and Samoa, the first major foreign tour since his life-changing cancer diagnosis earlier this year.

Thorpe is known for her attention-grabbing political stunts and fierce opposition to the monarchy.

When she was sworn into office in 2022, Thorpe raised her right fist as she begrudgingly swore to serve Queen Elisabeth II, who was then Australia's head of state.

"I sovereign, Lidia Thorpe, do solemnly and sincerely swear that I will be faithful and I bear true allegiance to the colonising Her Majesty Queen Elizabeth II," she said before being rebuked by a Senate official.

"Senator Thorpe, Senator Thorpe, you are required to recite the oath as printed on the card," said the chamber's president Sue Lines.

In 1999, Australians narrowly voted against removing the queen, amid a row over whether her replacement would be chosen by members of parliament, not the public.

In 2023 Australians overwhelmingly rejected measures to recognise Indigenous Australians in the constitution and to create an Indigenous consultative assembly.