In Western Australia at least 40 Aboriginal sites in the Pilbara are under threat from mining giant BHP Billiton as it seeks to expand its South Flank iron ore mining operation.

A BHP archaeological survey reveals rock shelters that were occupied between 10,000 and 15,000 ago and 22 identified sites of artefacts scatters, culturally modified trees, painted rock art and stone arrangements as well as “built structures” believed to be potential archaeological sites.

However plans to destroy the sites have been given consent by the West Australian government and under Section 18 of the state’s Aboriginal Heritage Act Banjima traditional owners are unable to lodge objections.

In a letter written to the WA government the Banjima people said they did not support the destruction of the sites and would “suffer spiritual and physical harm if they are destroyed”.

A BHP report from last year said while it took into account the views of traditional owners, it was “not reasonably practicable” to avoid damaging the sites.

The revelations come following an apology by Rio Tinto chief executive Chris Salisbury for destroying ancient sites in the Pilbara last month, an act which prompted widespread anger and protests outside the company’s headquarters in Perth.