The announcement comes less than a week after the carrier's retail partner Carphone Warehouse was reported to have run dry of its supply of 16GB iPhones.
Prior to that, both O2 and Carphone Warehouse announced that the 8GB iPhone was out of stock and would not be restocked because it had been discontinued.
Though O2 does not explain the sudden lack of availability, it's clear to industry watchers that Apple in recent weeks has been depleting Europe of its existing iPhone inventory ahead of a second-generation model that will run on faster 3G wireless networks.
Update: O2 has reportedly told Register Hardware that its currently in the process of replenishing stocks of the 16GB iPhone to be sold online, but that its retail stores still have the model in stock.
Update 2: O2's website is again reflecting stock of the 16GB model.