When I first went to Hiroshima in 1967, the shadow on the steps was still there. It was an almost perfect impression of a human being at ease: legs splayed, back bent, one hand by her side as she sat waiting for a bank to open.

At a quarter past eight on the morning of August 6, 1945, she and her silhouette were burned into the granite.

I stared at the shadow for an hour or more, then I walked down to the river where the survivors still lived in shanties.

I met a man called Yukio, whose chest was etched with the pattern of the shirt he was wearing when the atomic bomb was dropped.

He described a huge flash over the city, "a bluish light, something like an electrical short", after which wind blew like a tornado and black rain fell. "I was thrown on the ground and noticed only the stalks of my flowers were left. Everything was still and quiet, and when I got up, there were people naked, not saying anything. Some of them had no skin or hair. I was certain I was dead."

Nine years later, I returned to look for him and he was dead from leukaemia.

"No radioactivity in Hiroshima ruin" said The New York Times front page on 13 September, 1945, a classic of planted disinformation. "General Farrell," reported William H. Lawrence, "denied categorically that [the atomic bomb] produced a dangerous, lingering radioactivity."

Only one reporter, Wilfred Burchett, an Australian, had braved the perilous journey to Hiroshima in the immediate aftermath of the atomic bombing, in defiance of the Allied occupation authorities, which controlled the "press pack".

"I write this as a warning to the world," reported Burchett in the London Daily Express of September 5,1945. Sitting in the rubble with his Baby Hermes typewriter, he described hospital wards filled with people with no visible injuries who were dying from what he called "an atomic plague".

For this, his press accreditation was withdrawn, he was pilloried and smeared. His witness to the truth was never forgiven.