In the build up to long planned invasion of Nazi occupied Europe, Operation Overlord, nervous tension dominated the Supreme Headquarters Allied Expeditionary Force (SHAEF) headquarters. When a series of crossword clues appeared in the Daily Telegraph with answers that were closely guarded operational codewords, the spooks were spooked. Had the whole plan been blown by a puzzle?

The clue seemed innocuous: Red Indian on the Missouri. But the answer, Omaha, was the codename for the Normandy beach to be stormed by the 1st US Assault Division. On its own, this wouldn’t have raised any eyebrows. But it was far from an isolated example.

In the weeks building up to D-Day, the Telegraph’s crossword puzzle had featured a series of answers taken straight from the codebook at SHAEF headquarters. Utah, Juno, Gold and Sword all appeared, all four codenames for other targeted Normandy beaches. These would be followed on 27 May 1944 with Overlord, on 30 May 1944 with Mulberry (the name of the artificial harbours to be floated on to the beaches) and on 1 June 1944 with Neptune – the codename for the naval assault on France.

One or two of these answers would have passed innocuously enough, but could printing clues giving Juno, Gold, Sword, Utah, Omaha, Overlord, Mulberry and Neptune be simply coincidence? MI5 was unconvinced, and sent agents to question the compiler of the Telegraph crossword, Leonard Dawe, at his home in Leatherhead. According to a Telegraph article, the intelligences services took it seriously, with Dawe quoted as saying:

“They turned me inside out. They went to Bury St Edmunds where my senior colleague Melville Jones (the paper’s other crossword compiler) was living and put him through the works. But they eventually decided not to shoot us after all.”

Had MI5 cracked a secret Abwehr spy ring? Or was this simply the most amazing coincidence in history? The former is almost certainly untrue, but it also seems impossible that so many words from the codebook would be used as answers.

Perhaps the most convincing explanation is that at the time the south of England bristled with the accumulated military might of the United States, Britain and her Commonwealth allies. Certain words would be overheard and consciously or subconsciously absorbed to find themselves percolated as crossword answers.