The World Monuments Fund says up to 1 million images – some 10,000 years old – are carved into rocks on the Burrup. The heritage group, based in New York, added the Burrup Peninsula to its list of the world's 100 most endangered heritage sites earlier this year.

The organisation said previous industrial development in the area had destroyed 20% of the area’s rock art and expanding industry in the area would compromise the surviving petroglyphs.

“Twenty percent of the rock art has already been destroyed by industrial development and what remains is rapidly deteriorating due to airborne pollution,” the organisation’s website states.

“The government of Western Australia is planning to expand the industrial complex to comprise 38% of the rock art area. This will certainly compromise the portions that have not yet been damaged.”

The World Monuments Fund says its preferred option – which is supported by the Western Australian Greens – is for industrial development to be relocated to a site in the Pilbara which would pose no risk to ancient rock art.

But Western Australian Minister for State Development, Clive Brown, says the next best option, the Maitland Estate south of Karratha, would entail developing West Intercourse Island as a port which would affect even more rock art.