Explosives detonated in an area of the Juukan Gorge last month destroyed two deep-time rock shelters, causing great distress to the Puutu Kunti Kurrama and Pinikura people.

Rio Tinto iron ore chief executive Chris Salisbury says the company is sorry and wants to repair its relationship with traditional owners, but refuses to say whether reparations are being considered.

"Regrettably, we thought we had a shared understanding with the PKKP people about this site," told ABC radio on Friday.

"Something's gone terribly wrong here and we've committed to a comprehensive review of all of our heritage processes and moreover, committed to advocating for legislative change."

PKKP Aboriginal Corporation director Burchell Hayes said information provided by Rio Tinto to traditional owners was sometimes "at a level that is difficult for our elders to understand".

Rio Tinto claimed in an email to staff that there was no record of the PKKP asking the company to stop mining in the area until mid-May when the blasting was already loaded.

"We delayed the activity of the blast to see what we could do to stop it, but after a safety assessment of the situation, we had to go ahead," the email read.

But Mr Hayes rubbished any assertion that Rio Tinto was unaware of concerns.

"That isn't true because for years, we have made mention how significant those sites were."

The mining giant was granted approval for work in 2013, but subsequent archaeological excavation salvaged 7000 artefacts, including grinding stones, a bone sharpened into a tool and 4000-year-old braided hair.

In a 2015 documentary, funded by Rio Tinto, traditional owner Harold Ashburton said he had taken his sons to the area.

"I showed them Brockman, where my grandfather was born," he said.

"They turned and said, 'It's f***ed because of mining. What (have) they done to the country?'"

Mr Hayes said PKKP lawyers contacted the federal government shortly before the blast but made little headway.

"It is (disappointing) because now it's far too late, it's already happened," Mr Hayes said.

"I don't know whether or not there's any authority federally that could have prevented the destruction."

Greens leader Adam Bandt said Mr Salisbury should resign or be sacked.

"Rio can't just wash its hands and move on. They can't walk away from this. Responsibility rests at the top."

Mr Hayes said he did not have the strength to tell one senior elder about the loss.

"That's her father's country. We named that gorge after her father, my grandfather."

Premier Mark McGowan said the state government was working on legislation to ensure similar "traumatic" destruction never happened again.

Australian Associated Press