FMG breach comes on the heels of BHP's revelation of a disturbance at Mining Area C.
It is alleged KGH destroyed the Garnkiny sacred site on Gija country without consent.
Miners face up to $10 million in fines if they breach the law.
Protesters outside Rio's HQ in Perth call for heads to roll over the destruction at Juukan Gorge.
Vows to work with Puutu Kunti Kurrama and Pinkuru people on its heritage framework.