Captain Detmers' book revisitedArchived 29 May 2008 at the Wayback Machine (pdf) pp.7-8 The Australian Association of Maritime History. Admiral Karl Dönitz in 1959 confirmed that Allied codes had at that time been broken and that German raiders were in possession of the procedures for challenge and reply. It is possible that Detmers possessed the Straat Malakka's secret callsign, although he denied it. This might explain why Sydney was so close.
Captain Detmers' book revisitedArchived 29 May 2008 at the Wayback Machine (pdf) pp.7-8 The Australian Association of Maritime History. Admiral Karl Dönitz in 1959 confirmed that Allied codes had at that time been broken and that German raiders were in possession of the procedures for challenge and reply. It is possible that Detmers possessed the Straat Malakka's secret callsign, although he denied it. This might explain why Sydney was so close.