I just heard about the outrageously high levels of radioactivity (incredibly unsafe to humans) at that site on Fox news. Yes, the IAEA had visited there in the past. We'll hear alot more about this in the very near future. I have no doubt that there will be plenty of smoking guns to satisfy the most demanding skeptics---especially once the situation emerges where informants will become confortable enough to come out of the woodwork to point out and identify all the hidden caches of deadly materials--and that won't take very long.
A littel patience here will go a long way, IMHO.