From the longer Wikipedia page [1]

Leonard Sydney Dawe (3 November 1889 – 12 January 1963) was an English amateur footballer who played in the Southern League for Southampton between 1912 and 1913, and made one appearance for the England national amateur football team in 1912. He later became a schoolteacher and crossword compiler for The Daily Telegraph newspaperand in 1944 was interrogated on suspicion of espionage in the run-up to the D-Day landings.

Two days before the disastrous Dieppe raid in August 1942, the clue "French port (6)" appeared in the Daily Telegraph crossword (compiled by Dawe), followed by the solution Dieppe the next day; on 19 August, the raid on Dieppe took place.

In May 1944, Utah appeared as a solution in a Daily Telegraph crossword that was to have major repercussions. Utah was also the codename for the D-Day beach assigned to the 4th US Assault Division. This would have been considered a coincidence; however, in previous months the solution words Juno, Gold and Sword (all code names for beaches assigned to the British) had appeared and then on 22 May 1944 came a clue with the solution Omaha (code name for the D-Day beach to be taken by the 1st US Assault Division). Overlord (code name for the whole D-Day operation) appeared on 27 May and the pattern continued with Mulberry (code name for the floating harbours used in the landings) appearing on 30 May until finally, on 1 June, the solution to 15 Down was Neptune (code name for the naval assault phase).

MI5 became involved and called on Dawe, the compiler of the puzzles in question, at his home in Leatherhead. Dawe recalled the episode in a BBC TV interview in 1958. In 1984, Ronald French, a property manager in Wolverhampton, came forward to claim that, as a 14-year-old at the school in 1944, he inserted the names into the puzzles. According to French, Dawe occasionally invited pupils into his study and encouraged them to help fill in the blank crossword patterns. Later, Dawe would create clues for their solution words. French claimed that during the weeks before D-Day he had learned of the codewords from Canadian and American soldiers billeted close by the school, awaiting the invasion. French believed that hundreds of schoolchildren must have known what he knew

See also [2].