MELBOURNE – Rio Tinto ignored repeated requests from traditional owners for sacred Australian rockshelters to be protected in the months before the site was blasted during a mine expansion, an Indigenous group said on Friday.

The world’s biggest iron ore miner in May destroyed the two caves in Western Australia, sparking an outcry from the public and Rio's investors. One of the caves showed evidence of 46 000 years of human habitation, making it some of the earliest evidence of human civilisation.

Representatives of the Puutu Kunti Kurrama and Pinikura (PKKP) peoples sent communications as early as 2008, setting out the importance of the site before preservation efforts picked up in the months before the blast - but they went unheeded, the group said in a submission to a government enquiry.

"We are extremely angry that, over an extended period, Rio Tinto did not act on our input nor the input of specialist archaeologists and anthropologists relating to the cultural importance of the Juukan Gorge rockshelters," the group said.

"We are also angry that, once we raised the alarm bells in the months and weeks leading up to the disaster, Rio Tinto ignored our requests and concerns."

Rio Tinto declined to comment on the report but has noted that concerns over the site's significance were not elevated to senior executives, including CEO Jean-Sébastien Jacques and two others who ultimately lost their jobs over the destruction.

The Indigenous group set out a string of perceived failures and what they called "misrepresentation" by the company in their 120-page report, which is likely to ratchet up pressure on Rio's board, the Western Australian mining industry and the state government, which allowed the blasting.

It also accused Rio of withholding important information at critical junctures before the blast and of laying explosives even after agreeing to freeze its detonation plans.

"The destruction ... has caused immeasurable cultural and spiritual loss and profound grief to the PKKP People," the group said.

The culture that prioritised profit and minimal heritage preservation was not confined to Rio Tinto, the group said as it called for wider reform of "inadequate" legislation.

"The problems within Rio Tinto ... are deep-seated and systemic and revolve around culture and behaviour," it said.

"The same culture is exhibited by the overwhelming majority of resource industry proponents in Western Australia."

The destruction has triggered pledges by other major miners such as BHP Group and Fortescue to review their mine plans.

"We believe that Aboriginal culture and heritage is undervalued in Australia and throughout the world. Steps need to be put in place to adequately protect, rehabilitate, capture and celebrate it," it said.

The enquiry continues next month.