A British mathematician, I.J. Good, who was a veteran of the World War II codebreaking group at Bletchley Park, once published a paper listing "k. Caj Doog" as co-author (an obvious rearrangement of the letters of Jack Good). When asked subsequently about the status of his collaborator, Good replied that he lost contact with Doog after the Chinese Communists overran Tibet.
Golomb, Solomon W.
Word Ways: Vol. 47
, Article 8.
Available at: https://digitalcommons.butler.edu/wordways/vol47/iss1/8