Daniel Duggan was arrested in October last year at the request of American authorities, who allege he helped train members of the Chinese military to fly jet fighters.

In December, the federal government approved a request from the US to extradite the 54-year-old, which his lawyers are now fighting.

Sydney's Downing Centre Local Court was today told his legal team has sent requests to multiple Australian agencies for information relevant to preparing a defence, but in some cases they have been refused access and are now appealing.

Mr Duggan's lawyer, Dennis Miralis, requested a further six weeks to continue pursuing the documents, but Trent Glover, for the United States, pushed for a shorter adjournment, saying it was "time to move the matter along".

Magistrate Greg Grogin allowed the extra time, noting there were important decisions to be made.

"A man's liberty is at stake here," he said.

Outside court, Mr Miralis revealed there were 63 documents relevant to their requests for material to better understand how Mr Duggan was indicted, which were "crucial" to his preparation of a defence.

Requests were made of ASIO, the Australian Criminal Intelligence Commission, Australian Federal Police and the Attorney-General's department, he said.

"We hold grave concerns about whether or not there was compliance at law with the mutual legal assistance requests made by the US to Australia at a point in time when Daniel was, in fact, solely an Australian citizen," Mr Miralis said.

He said the AFP refused to provide access to material, citing the potential prejudice to extradition proceedings.

Mr Miralis described that as an "intolerably improper response".

Mr Duggan applied for a government job in Australia which required security clearance and Mr Miralis said authorities were aware of his movements.

He was granted security clearance by ASIO prior to returning from China in 2022 to obtain an aviation licence, but a few days after his arrival the clearance was removed, Mr Miralis said.

"It's striking to us that a sequence of events like that could occur," he told reporters.

"We are exploring at this stage whether or not he was lured back to Australia by the US, where the US knew that he would be in a jurisdiction where he would be capable of being extradited back to the US."

Mr Miralis said lures were commonly used by US authorities and were legal under US law, however if one was deployed with the cooperation of Australian security agencies — by "Manipulation" of security clearances — it would be "A matter of grave significance".

"At this stage, these are matters under investigation," he said.

"We're not able to go any further than that, other than to highlight that we require the information to be able to ensure that the whole process of his return to Australia was not done in a way which was inconsistent with law."

The case returns to court on May 1.

Original Story By | Jamie McKinnell