On her way to Penang on Nov. 11, 1940, the Blue Funnel Line merchant vessel SS Automedon was sunk by the German raider Atlantis masquerading as the British auxiliary cruiser Antenor, southwest of Achin Head on the northwestern tip of Sumatra.
Before the ship was sunk, the Germans discovered "Most Secret" papers being sent to the British commander in chief in the Far East. They "contained extremely detailed information on the Royal Navy's and the RAF's armaments and positions, the defence of Singapore and possible response measures to Japanese aggression, as well as an analysis of the roles of Australia and New Zealand."
This was a hugely important find and so steps were taken by the German commander of the Atlantis, Captain Rogge, to ensure that the papers were delivered as soon as possible to German intelligence in Japan. They were then soon in Japanese hands.