SYDNEY — An Aboriginal protester has been arrested at the Sydney Opera House as crowds await a glimpse of King Charles and the Queen on the final day of their tour in Australia.

Throngs of people have packed the harbourside forecourt, where the royal couple are due to visit on Tuesday afternoon.

Wayne Wharton, a prominent Indigenous activist from Brisbane, was arrested after shouting anti-monarchist slogans and refusing a police order to move on.

It comes as backlash over an Aboriginal senator's heckling of King Charles in Canberra on Monday intensifies.

Wharton had shouted "he’s not my King", echoing the words of independent Senator Lidia Thorpe the day before.

The crowd waiting for the royals — many clutching mini union jack flags — shouted back "God save the King".

Wharton had also protested outside the church service the royals attended on Sunday.

Thorpe's protest has been praised by some Indigenous activists as brave, but condemned by other prominent Aboriginal Australians as "embarrassing" and disrespectful. It has also been roundly criticised by her parliamentary peers.

On Tuesday, Thorpe said she had deleted a violent cartoon of the King that was posted to her Instagram account, describing it as "inappropriate" and posted by a staff member without her knowledge.

Outside the Sydney Opera House, onlookers applauded officers when Wharton was arrested and placed into a police van.

Many of the hundreds there had been queuing since early on Tuesday, a few draped in British flags. Others had accessorised with royal-themed jewellery and handbags.

“We want to celebrate our country and all the people in it,” said Karen Clark, with her little boys Benjamin and Harrison who were both wearing crowns and capes with a fake fur trim.

“We were brought up with the King, we celebrate the King’s birthday with the boys — it’s fun to have high tea and dress up in our best outfits.”

Bettina Bethuel, who came with her friend Taja Shephard, said: “My father was from Liverpool and I’ve always been interested in the royals."

Taja saw the heckling by Thorpe on TV and wasn’t impressed.

“I thought it was a little rude but I suppose she makes her point for Indigenous people,” she said. “But I don’t think it’s appropriate how she behaved.”

Nellie Pollard-Wharton, who was with her father as he was arrested, said it was "laughable" to watch crowds "cheering as he’s put into a paddy wagon [police van] for standing up for his rights".

"Essentially, in the vein of what many Aussies say to us, it’s like ‘get over it’ — it’s been long enough," she told the BBC.

"[But we] need to keep resisting so we can have treaties, so we can have our rights heard, so our young people and our men and women in custody stop dying, so that our health outcomes improve... so we can actually self-determine."

On the other side of the city, King Charles began Tuesday with a visit to the National Centre of Indigenous Excellence in Redfern, where he met with Aboriginal elders.

He later attended a community picnic in Parramatta, where the suit-clad monarch had a go at cooking sausages on a barbeque before meeting a sheepdog. — BBC