In Biggles Hunts Big Game, John Robinson was an operative of the international counterfeiting gang headed by Kravas. Biggles first met Robinson within hours of being assigned to investigate the gang. Robinson had called on Biggles at his Mount Street apartment in order to bribe him. He offered Biggles a better paying job and gave Biggles a gift of a thousand pound note which Biggles promptly burnt. Knowing that bribery had failed, Robinson next offered Biggles a cigar, which Biggles decline to light in his presence. Biggles later discovered this cigar had a bombed inserted inside it. Knowing this second move had failed, Robinson hastily took his leave, but he had planted an operative at the building entrance to prevent Ginger from following him or nothing his cab number and another operative posing as a news vendor on the street to mount surveillance over Biggles' residence.
Ginger and Bertie later met Robinson again on the plane travelling from Cairo to Kudinga. Robinson remained at Kudinga for the rest of the story and he was arrested by the Egyptian police when the place was raided at the end of the book.
John Robinson was probably an assumed name. When he introduced himself in Biggles' apartment at the beginning of the book, Ginger observed that he had spoken his name in such a way as to suggest that it was an assumed name and that he intended it to be realized as such. Robinson was described as a typical prosperous looking businessman with a confident bearing and shrewd apprizing eyes in his early fifties. His hair and thick moustache were black and together with his dark complexion, suggested that he must have Latin American or Mediterranean ancestry. His clothes were of high quality but he wore tightly fitting patent leather shoes, which Ginger observed must be a foreign touch because it was something "few Britishers would wear except with evening kit".