I suspect that this is Austroboletus eburneus/niveus. There was a bit of confusion as to if these were two separate species or in fact one species. I'll check up on what the latest view on this is and get back to you. Regardless, it's a great looking fungus.........good find. If it's possible in future images to try and get a bit more light on the underside (in this case pores) or different setting to show details more clearly.