LONDON – A pillar of the British establishment was passing secret information about aviation design to Japan during the 1920s, according to secret government files declassified Thursday.
The British Foreign Office files from 1926 show that Lord Sempill, reputedly one of the founders of the Royal Flying Corps in World War I, passed details of British “aeronautical construction” to the Japanese naval attache in London, Capt. Teijiro Toyoda.
The records, which have remained classified for the last 75 years, indicate that the espionage took place roughly between 1922 and early 1926.
He escaped prosecution only because MI5, the British counter-intelligence agency, wanted to protect its operation monitoring diplomatic mail to and from the Japanese Embassy in London, according to the records.
Sempill, who died in 1965, had worked in Japan as part of the British air mission and served as an adviser to the Japanese naval air force. From the files, it would appear that Sempill was stationed in Japan between 1920 and 1922.
Sempill was apparently well respected within Japanese circles and received a personal letter from then Prime Minister Tomosaburo Kato (1922-1923) thanking him for his work with the Japanese navy, which he described as “almost epoch-making.”
The files show that after his return to Britain, intelligence services in Britain became suspicious about his activities and obtained a warrant from the home secretary to search Sempill’s home.
They found correspondence between the Japanese naval attache and Sempill. In addition, there was evidence that Sempill had been paid for his services.
According to the files, Sempill also tried to obtain details of a secret seaplane, code-named Iris, which was being built by a British company where he also acted as an adviser.
Sempill allegedly tried to get the information by entering the plane’s hangar and talking to the staff.
It is unclear from the documents if any secret information was gleaned and whether it was passed on to Japan.
The Foreign Office became involved in the Sempill case after learning that he was on the verge of being appointed Greece’s aeronautical adviser in March 1926.
The Security Services advised the Foreign Office and the British Embassy in Athens that Britain could not be seen to endorse Sempill’s appointment because of his past activities.
However, public prosecutors decided not to press charges against Sempill, as the evidence against him involved photographic copies of letters written by Sempill to the attache, and the British government would have had to reveal how it got the information and disclose its sources.
Prosecutors also believed it would be hard to take action against Sempill with regard to the seaplane incident because he served as an occasional adviser to the company, and the employees he talked to might not have actually considered their project as being top secret.
Sempill, frustrated by what he regarded as a whispering campaign designed to stop him from getting the appointment in Greece, demanded to see security chiefs.
At the meeting, they told him that they were aware of his links to the Japanese attache. The documents say Sempill apparently realized that he had been lucky not to be charged for his actions and withdrew his complaint.
The Daily Telegraph on Thursday described Sempill as a “pillar of the British establishment” and pointed out that his father was an aide to King George V.
Sempill was chairman of the Royal Aeronautical Society in 1926 and served as a member of the Royal Naval Air Service between 1939 and 1941, the newspaper said.
Japan awarded Sempill the Order of the Rising Sun in 1961.