Foreign Correspondent understands that in 2004, the then-Australian defence minister, Liberal senator Robert Hill, notified the Americans of his intention to announce the flights to the Australian public.
But the US Air Force vigorously opposed the defence minister's planned disclosure, demanding all Global Hawk operations remain classified.
Mr Hill, who has since left federal Parliament, did not respond to requests to comment on this story.
South Australia's then Labor premier, Mike Rann, who at the time was lobbying for a greater Defence presence in his state, was not told of the sensitive US military flights
