MELBOURNE – Mining giant Rio Tinto has not formally committed to review the terms of an iron-ore mine development that would let it destroy 124 culturally significant sites, a group representing Aboriginal traditional owners said on Monday.

Addressing a Parliamentary panel examining how Rio legally destroyed sacred and historically significant rockshelters in Western Australia state, the head of the Yinhawangka Aboriginal Corporation said Rio had stopped short of promising any review.

"Rio have stated in various forums that they will consider reviewing the agreement....(but) we don’t have a formal commitment," CEO Grant Bussell told the inquiry.

Rio's CEO Jean-Sebastien Jacques and two deputies said this month they would step down following a public outcry over the incident in the state's Pilbara region, and how the company handled it.

Rio had not done an adequate job of protecting an existing sacred site, Yinhawangka archaeologist Anna Fagan told the inquiry, raising concerns over how the rest of the cultural heritage would be managed.

"We have 327 heritage sites and 124 will be destroyed by the Western Ranges expansion project by Rio Tinto," she said.

The inquiry has revealed that Indigenous groups have been subject to confidential contracts barring them from objecting to any mining development on their ancestral land, prompting questions over whether the miners gained full and fair consent.

"No one says, in return for getting these (agreements), you don’t have any rights in protecting your country," Bussell said.

Peer BHP has promised not to act on historical approvals to damage sites while it held fresh talks with traditional owners.

In a statement, Rio said it was building on decades of deep engagement as it assessed the sites to gain better understanding of "the cultural significance and values placed on these sites by the Yinhawangka People."

It added that it had committed to modernise its pacts, including details around the issue of consent, with all the groups on whose lands it operates in the Pilbara.