“Since 1973, when the National Gallery acquired Jackson Pollock’s Blue Poles, there has been a dynamic discussion on the artistic merits of works in the national collection, and/or on display at the gallery,” it said.

“We present works of art to the Australian public to inspire people to explore, experience and learn about art.”

The gallery in Canberra has since received more than a dozen complaints about the painting from individuals connected to Hancock Prospecting, Ms Rinehart’s company, the Sydney Morning Herald reported.

Ms Rinehart is worth an estimated £19 billion, and is considered the richest woman in Australia. Hancock Prospecting was founded by her father, Lang Hancock, in the 1930s.

The company has been the target of anti-racism campaigns after its founder said in the 1980s that indigenous Australians should be “sterilised”.

In 2023, Ms Rinehart withdrew her AUD £15 million sponsorship of Netball Australia after Donnell Wallam, an indigenous player, said she would not wear a strip with the Hancock Prospecting logo.

Namatjira was the first Aboriginal artist to win the prestigious Archibald Prize with his portrait of Adam Goodes, a former Australian Rules football player, in 2020.

The National Gallery of Australia describes his paintings as “laden with dry wit” and the artist as “a celebrated portraitist and a satirical chronicler of Australian identity”.

Another of his paintings in the exhibition depicts King Charles III in formal dress, standing in the Australian desert.