MELBOURNE - An Australian Aboriginal group whose sacred rockshelters Rio Tinto destroyed in May said on Monday that iron ore miner Fortescue Metals Group applied last month for a mining licence on the surrounding area without notifying them.

Speaking at an Australian parliamentary inquiry into the Juukan Gorge disaster, in which Rio Tinto destroyed a 46 000 year old rockshelter in Western Australia that shed light on humankind's development, cultural heritage expert Heather Builth said traditional owners had worked hard to secure a moratorium with Rio over the area after the blast.

The moratorium over the disturbed area and surrounds which was agreed with Rio for six months, was to help better investigate the region that showed evidence of continual human habitation back through the last ice age, and was sacred to the Puutu Kunti Kurrama and Pinikura (PKKP) men's spiritual business, Builth said.

However, Fortescue had applied for a mining licence on September 27 on the area that the traditional owners had identified as high cultural sensitivity and had not informed them.

"We are working with FMG, we have meetings with FMG but we weren't told of this - we had to find it out ourselves," she told the inquiry. "We are very worried. Especially since we haven't finished our cultural mapping, our landscape understanding of that area," Builth said.

"It is insensitive to say the least, it is unconscionable to say the most."

Fortescue CEO Elizabeth Gaines confirmed that Fortescue had applied for a mining lease over an area approximately 10 km (6.2 miles) from Juukan Gorge as per industry practice, for which it had prospecting licences granted in 2012 that were about to expire.

There were no current plans to mine the area, she said in a statement adding that Fortescue had begun discussions with the PKKP about conducting extensive heritage surveys of the area. "We take our relationship with Traditional Custodians very seriously and, we will continue to work with the PKKP to survey the area and understand areas of cultural significance."

The destruction of two rockshelters and outcry at the light sanctions doled out by Rio's board cost CEO Jean-Sébastien Jacques and two executives their jobs as well as triggering a widespread review by peers including BHP Group and Fortescue of their heritage management.

The PKKP have spoken rarely since the blast, partly due to strict confidentiality clauses in their mining agreements which have inhibited them from speaking freely about their heritage concerns outside the inquiry, PKKP Corporation CEO Carol Meredith said at the inquiry.

Rio has said that it is open to reviewing clauses in its contracts that restrict the PKKP and other traditional owner groups from publicly opposing or criticising its planned mining developments.