Long before the NSA was reading our email and listening in on our phone calls, there was D Special Section – a crack team of code-breakers who helped turn the tide in the Second World War by listening in on Japanese diplomatic cables. Now their story is being told, reports BELINDA CRANSTON.

David Sissons was a shy academic. He quietly worked away at the Department of International Relations at ANU for decades, researching, publishing and making discoveries.

While he is sadly no longer with us, his presence and his remarkable findings are still being felt.

His knowledge of a clandestine code-breaking organisation is out in the open, after colleagues in the ANU College of Asia and the Pacific resuscitated his painstaking research years after his death.

The Diplomatic Special Section (D Special Section) was the most secret of the Allied code-breaking organisations in Australia during World War II.

Operating out of humble inner Melbourne offices, it began decrypting intercepted Japanese diplomatic communications in 1942, and later also received intercepted Russian traffic.

David Sissons, just 18 and not long out of Scotch College, Melbourne, where he excelled in mathematics, was hired as a linguist and translator, from April until September, 1945.

He went on to specialise in Australia-Japan relations at ANU and was intent on publishing an account of the small intelligence agency, along with a top secret report on its cryptanalytical activities – but in 2006, died before finishing the project.

Now a new book edited by ANU academics Professor Desmond Ball and Dr Keiko Tamura, Breaking Japanese Diplomatic Codes, David Sissons and D Special Section, pays tribute to his research, while also acknowledging the select group of mathematicians, classicists and others who worked for the covert agency.

Prompted in 1978 by articles written by Ball and fellow ANU Professor David Horner about their awareness of his former unit, Sissons made it his mission to gather as much information as he could on its history and activities.

But there was scarce material available.

When former D Special Section colleagues Ronald Bond and Ian Smith told him in 1986 of a post-war, top secret report they had compiled, he persisted in getting a copy – which intelligence agency the Defence Signals Directorate finally released in December 1996.

The slightly edited 45-page report, along with a 13,000 word introduction by Sissons, forms one part of Ball and Tamura’s book.

Interestingly, the covert report ceased to be publicly available after 2011.

Ball suggests DFAT lawyers may have arranged for its removal.

“The Australian Government consistently refused to admit that it ever intercepted diplomatic communications, even in wartime,” he says.

“After all, it was and still is a signatory to Vienna and Geneva conventions on diplomatic relations under which the host country must permit and protect communication between the diplomats of the mission and their home country.”

A young David Sissons.

There is evidence to suggest D Special Section became involved in the beginnings of Australia’s most serious espionage episode.

In a “top secret” letter dated January 6, 1945, General Sir Thomas Blamey, Commander-in-Chief of the Australian Military Forces, warned of information leakages out of Australia that had apparently originated in Canberra.

Addressed to the Acting Minister for the Army, the letter gave four examples of the Japanese receiving Allied plans ‘for certain operations in the Philippines’ and details of recent Australian army intelligence estimates of Japanese strength there.

Instances of similarly leaked information were sourced to the Soviet embassy in Canberra.

“What concerned Blamey, was how our war plans got from Australia to the Soviet Union, and then from Moscow to Tokyo,” says Ball.

Declassified files in the UK National Archives indicate a London based agency deciphered the Japanese traffic, then alerted Blamey of the leaks.

Ball believes at least some of the messages would have been forwarded to London by D Special Section, which received messages for decryption from radio intercept stations at locations such as Mornington, 40 kilometres southeast of Melbourne.

By December 1945, after Japan’s surrender in August, the Mornington station was devoted almost entirely to Russian transmissions.

The sinking of HMAS Sydney
D Special Section also had prior knowledge of one of Australia’s most famous military mysteries.

Long before a 2009 Commission of Inquiry established German raider ship Kormoran sank HMAS Sydney off the coast of WA in November 1941, ending decades of speculation as to how she met her fate, Sissons’ research reveals the same explanation was available much earlier.

An encoded account of the battle by Kormoran’s captain, Commander Theodor Detmers, was passed to D Special Section to be deciphered after he escaped from a POW camp in Victoria and was later captured in January 1945.

According to Ball, because D Special Section was a top secret organisation, the government could not release the information contained in Kormoran’s cryptogram.

D Special Section and ANU academics
The main code-breaker for D Special Section, Arthur Dale Trendall, went on to become Deputy Vice-Chancellor and Master of University House at ANU. He retired from the university in 1969.

Renowned for his phenomenal visual memory, the professor of Greek and archaeology was also a leading expert in reconstructing broken ancient Greek ceramic vessels.

Ball and Tamura believe that although Sissons and Trendall’s time at ANU overlapped, they never discussed their D Special Section work.

Kenneth McKay, who later became reader in classics at ANU, was also a D Special Section alumni.

The Sissons legacy


Sisson’s death in 2006 came after a long career at ANU spanning almost four decades. His influence is still felt almost a decade later.

Sissons’ first PhD student, Professor Arthur Stockwin, now a distinguished scholar in Japanese studies at Oxford University, visited ANU in 2010 and 2011, to assist Bell and Tamura with writing their book on his work.

“Arthur knew that David, who had this reputation for poor productivity, was in fact very productive,” says Ball.

“And that he had a lot of work in his filing cabinet that just hadn’t been published.”

The reticent perfectionist, whose work now fills 60 archival boxes in the National Library, was more comfortable sharing his knowledge with others than promoting his own research, says Tamura, a researcher at the ANU College of Asia and the Pacific.

“People had to go through formal procedures to get to know him,” explains Tamura, who first met Sissons during the 1990s.

He requested a formal introduction from her then supervisor, when she was completing a PhD thesis in anthropology at ANU.

“But once you were trusted, he was most generous in sharing his knowledge and expertise with you,” she says.

Of Sissons’ doggedness in getting a copy of the report on D Special Section, Ball says: “It is very likely that the 1946 cryptographic report would have remained unreleased and unknown, were it not for his persistence, fuelled by his knowledge of its existence.”

The discovery paves the way for a whole new area of further research.

Up until the release of the 1946 cryptographic report, information was available on only two of the three code breaking organisations Australia hosted during World War II.

“It is only now, that war historians can really fill that gap, that one third of the code breaking picture, and get the real answer as to how we won the war, about how we defeated the Japanese,” says Ball.

Breaking Japanese Diplomatic Codes is available through ANU E press.

More: watch a video with Professor Des Ball and Dr Keiko Tamura discussing David Sissons and D Special Section.