Rio Tinto proceeded with destroying ancient and culturally significant sites in Western Australia so it could dig up an extra $135 million worth of high-grade iron ore, the mining giant's chief executive has told a Senate inquiry.
Jean-Sebastien Jacques has also said he only learned of the significance of the Juukan Gorge rock shelters after they were blown up.
Rio in May destroyed the 46,000-year-old landmarks on Puutu Kunti Kurrama and Pinikura (PKKP) country in the Pilbara region.
The company had secured consent under WA's Aboriginal Heritage Act in 2013, but has admitted subsequently overlooking information about the sites' significance.
Mr Jacques was one of several Rio executives grilled by members of the Northern Australia Committee on Friday.
"The events at Juukan should not have happened," he told the inquiry.
"This is a defining moment for Rio Tinto and we are absolutely committed to learn and change."
The Sydney-based CEO said Rio had three options to expand its Brockman 4 mine without damaging the Juukan Gorge sites but chose a fourth option to destroy the caves.
This enabled the extraction of an additional eight million tonnes of high-grade ore with a net present value of $135 million, he said.
Mr Jacques confirmed traditional owners were not informed Rio had examined the less damaging development options.
Liberal MP Warren Entsch, the chair of the joint standing committee on Northern Australia, was stunned by the admission.
"That really bothers me," he said.
"It really beggars belief ... that there was no understanding by the executive within Rio that there was an issue on this site."
Rio reached a development agreement with the PKKP people in 2011.
But new information came to light when an ethnographic survey and archaeological excavations of the rock shelters were conducted in 2013 and 2014.
Rio received a report in 2018 revealing the existence of 7000 artefacts including grinding stones, tools and 4000-year-old braided hair.
By the time PKKP representatives learned the caves would be destroyed, blast holes had already been loaded with explosives.
Rio's Perth-based iron ore chief executive Chris Salisbury told the inquiry that was the "point of no return" for saving the site.
He also claimed he didn't know about the 2018 report until after the blast.
Mr Jacques said no one had been stood down or suffered financial consequences as a result of the company's mistakes.
An internal review is underway.
"We are absolutely sorry for what happened," he said.
"I can put my hand on my heart and say there is no one at Rio who wakes up in the morning and wants to do harm to Aboriginal heritage sites."
His predecessor Sam Walsh told the Australian Financial Review he issued instructions in 2013 not to destroy the site.
Mr Jacques said the company had checked its records and could not corroborate the claim.
Aboriginal people have no right of appeal under WA's existing approvals process.
Treasurer and Aboriginal Affairs Minister Ben Wyatt told the inquiry the government was close to finalising draft heritage reforms which will provide appeal rights and contingency arrangements for new information that arises.
He said Rio's actions had "hugely damaged" their brand but he hadn't previously had any issues with them.
"It's incredibly tragic for the PKKP people - a site that was clearly of incredible significance to them but it seems more broadly, incredible significance to Australia," he said.
Mr Entsch said Rio would be called to give further evidence at a later date because many questions were left unanswered.
Australian Associated Press