It is a crime the US has always denied – dropping germ bombs on North Korea.
But in 1952 the bubonic plague, never known before in North Korea, broke out across the country.
It claimed at the time that the United States was to blame. But the allegations were brushed aside as propaganda.
Sixty years later however, new evidence has emerged that bioweapons may indeed have been used.
Tim Tate reports exclusively for Al Jazeera.