An item in the Daily Telegraph (British 'newspaper') online 9 January said 2013.
Assuming this is genuine, it must have survived the US post-1945 censorship. The short piece claimed such a photo was known to exist; one has to guess it or was suppressed, as it's inconsistent with the idea of a single 'mushroom cloud'. (Elsewhere on this site we argue that the 'mushroom cloud' was probably a mistake that slipped into the fakery from the outset, and was retained because of its simple imagery; this happens with many frauds - think of 'gas chambers' for example).
A [black-and-white] recently found at the Honkawa Elementary school in Hiroshima city shows the mushroom cloud from the Hiroshima atomic bombing split in two which is believed to have been taken about half-an-hour after the bombing on August 6, 1945, from a location some 10 kilometres (six miles) east of the hypocentre.
Possibly the photo was known about, but not printed. Honkawa has a 'nuclear museum'; the photo could have been tucked away in a drawer, and rediscovered, and rather carelessly published, the original reason for censorship being forgotten. (This type of carelessness tends to happen when any fraud seems firmly established - think of 'atom test' films).
I don't know if the location has been identified; it's not stated if the photo has been cropped; possibly the docks/shores, rivers, hills are identifiable; maybe separated by water; and possibly two sites have been identified with two main targets of American bombings.
But clearly the photo is consistent with the few air photos of Hiroshima, in which two plumes have been photographed to appear as though they were one.
Thanks to ScreeOrTalus from Youtube for mentioning this.
Photos as published (side by side, together) online by the Daily Telegraph site, for Jan 9th 2013.
The right-hand photo looks fake to me; the pile of rubble with the foggy 'iconic' photo inserted behind.
