Successive Australian governments have consistently refused to admit Australia ever intercepted diplomatic communications, even in war-time.

Now a new book by ANU College of Asia and the Pacific academics Professor Desmond Ball and Dr Keiko Tamura lifts the lid on the most secret of the Allied code-breaking organisations in Australia during World War II.

Titled Breaking Japanese Diplomatic Codes, it recounts the history and activities of D Special Section, a small but very select group that decrypted intercepted Japanese diplomatic communications from humble Melbourne offices during World War II.

“To begin with, all of our code breaking activities were highly classified,” says Ball.

“The government has been very reluctant to say anything about the D Special Section because it was focused on breaking Japanese diplomatic signals.

“And Australia, like most countries in the world, is signatory to various Geneva and Vienna conventions, so in having an organisation which is concerned with monitoring someone else’s diplomatic transmissions, we are actually in breach of international law to which we are a signatory.”

Ball and Tamura’s book pays tribute in particular to the late David Sissons, who worked for D Special Section as a linguist and translator before he specialised in Australia-Japan relations at the ANU Department of Industrial Relations for almost four decades.

After learning of a post-war, top secret report on the activities of D Special Section, he spent decades hunting down a copy of the report, which is included in Ball and Tamura’s book.

The report, along with a previously unpublished account of the origins and history of D Special Section, which Sissons wrote in 2006, is also included.

“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,” says Ball.

D Special Section also had ‘inside knowledge’ of one of Australia’s most infamous military mysteries – the sinking of the HMAS Sydney.

Long before a 2009 Commission of Inquiry established German raider ship Kormoran sank HMAS Sydney off the coast of Western Australia in 1941, the book also reveals an encoded account of the battle, as told by the Kormoran’s captain Commander Theodor Detmers, was passed to D Special Section to be deciphered in 1945.

“Staff in this section decoded the message very quickly,” says Tamura.

“The content said the Sydney approached Kormoran very closely – too closely before it identified Kormoran was actually a German raider ship.”

Breaking Japanese Diplomatic Codes will be launched at Room 1.04, Coombs Extension Building (8), Fellows Road, ANU College of Asia and the Pacific at 5.30pm, this Wednesday 30 October. Register here to attend the event.

Breaking Japanese Diplomatic Codes is available through ANU E press.

Article by Belinda Cranston.

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