"...call a halt to it before any more public funds are squandered."

That assumes the money spent is squandered.  Maybe not.  Who knows for sure?

But, OK, let's call a halt.  But let's do it for one reason only: the indigenous peoples want to own and control it.  Good enough for me.  Let 'em go at it. Or not.  Once the budget on this thing is spent, that's it. If nothing concrete is discovered/acted upon, then who are the indigenous going to blame then?  THEMSELVES?  Certainly not us.  And then...never again with public money.