Rio detonated explosives in an area of the Juukan Gorge on Sunday, destroying two ancient deep-time rock shelters and causing significant distress to the Puutu Kunti Kurrama and Pinikura people.

The mining giant was granted approval for work in 2013, but subsequent archaeological excavation had revealed ancient artefacts including grinding stones, a bone sharpened into a tool and 4000-year-old braided hair.

Rio this week suggested representatives of the traditional owners had failed to make clear concerns about preserving the site during years of consultation between the two parties.

"We are sorry that the recently expressed concerns of the PKKP did not arise through the engagements that have taken place over many years under the agreement that governs our operations on their country," the company said.

But in a statement on Saturday, Puutu Kunti Kurrama and Pinikura Aboriginal Corporation (PKKPAC) spokesperson Burchell Hayes rejected the claim and said the significance of Juukan Gorge had long been emphasised.

"At all times, the PKKPAC has been direct and explicit in the archaeological and ethnographic significance of these rock shelters and the importance that they be preserved," he said.

"We believe Rio Tinto's outrageous statement is a bid to minimise the adverse public reaction and community outrage about Sunday's blast at Juukan Gorge; and the distress and upset caused to the Puutu Kunti Kurrama people."

Mr Hayes said PKKPAC only became aware of Rio's intention to blast the area in May when staff sought access in preparation for NAIDOC Week in July.

The Australian Archaeological Association said the fact Rio Tinto did not revisit the decision after the cultural significance was identified was "inconsistent with modern standards of heritage management".

Traditional owners are concerned the existing approvals system does not consider new information after ministerial consent has been granted.

Aboriginal Affairs Minister Ben Wyatt has said he was unaware of the blast or concerns beforehand.

The state government hopes to pass its new Aboriginal cultural heritage bill this year, although COVID-19 has delayed the consultation process.

"It will provide for agreements between traditional owners and proponents to include a process to consider new information that may come to light, and allow the parties to be able to amend the agreements by mutual consent," Mr Wyatt said.

"The legislation will also provide options for appeal."

Rio Tinto iron ore chief executive Chris Salisbury said the company took cultural heritage and its partnerships with Aboriginal groups seriously.

Australian Associated Press