A Nordic dog who answered to the name Hitler and was trained to make a Nazi salute was the subject of a high-level investigation by the German foreign office during the Holocaust.

Newly unearthed files have revealed that the paranoid German government saw the ability of Finnish businessman Tor Borg’s pet Jackie to make the Heil Hitler salute as an insult to the Nazi leader.

In 1941 Mr Borg was summoned to the German embassy in Helsinki to explain, while Finnish diplomats were commanded to compile evidence on the creature’s exploits.

His wife had started calling Jackie “Hitler” because he responded to the name by raising his paw as if he was greeting the Nazi leader.

The cables discovered by historian Klaus Hillenbrand even show plans to destroy Mr Borg’s pharmaceutical company as punishment for his dog’s insubordinate behaviour.

The Foreign Office in Berlin commanded its diplomats in the Nazi-friendly Nordic country to gather evidence on the dog and for some time considered pressing charges.

Mr Borg was forced to tell his interrogators that Jackie had done nothing "that could be seen as an insult against the German Reich,” but his explanation did not suffice.

In a cable to Berlin a Helsinki diplomat wrote: “Borg, even though he claims otherwise, is not telling the truth."

Mr Hillenbrand told the Associated Press: “Just months before the Nazis launched their attack on the Soviet Union, they had nothing better to do than to obsess about this dog.”