Most information regarding this incident is either still classified by Canadian, US, and British secret services, or, was destroyed with the death of the Spanish Dictator General Franco in 1975. From what is available historians have pieced together the following series of events.
In 1941 Canada severed diplomatic ties with Japan with the declaration of formal war and expelled the Japanese diplomats who had been in Canada. Spain, who had been officially neutral power in the war, took on the responsibilities of acting as a protectorate diplomatic mission to Canada for Japanese interests; specifically they became responsible for advocating for Japanese-Canadian interests in absence of the official Japanese representative. [1]
Allied powers were suspicious of Spain's neutrality, as General Franco was a fascist who seemed to sympathize with other fascist governments; similar to how the axis and so the Canadian government asked powers were suspicious of US neutrality. The examination unit was tasked with decrypting any communications with coming to or from Spanish diplomats in Canada. [1]
In August of 1943, a package intended for a Spanish diplomat in Vancouver, Fernando de Kobbe y Chinchilla (pictured above), was intercepted. Inside were 2 ciphers and encrypted instructions on how to make invisible ink. The ciphers were intended to be used by Kobbe to encrypt information to the Japanese government about any allied troop and navy movements. [1]
With this the Canadian government knew that Kobbe was spying on behalf of the Japanese government. Kobbe was expelled, but more crucially the Spanish government was implicated as an axis ally. [1]
Even after the Second World War ended Canadian authorities remained so offended about the incident that they delayed an exchange of ambassadors with Spain for eight years; Which is longer than it took to exchange ambassadors with Italy, Germany or Japan. [1]