A senior public servant accused of espionage activities has been denied access to evidence used to strip him of his security clearance.

The case stems from allegations by ASIO that Mr Yeon Kim, while employed with the Australian Bureau of Agricultural and Resource Economics, may have had contact with several successive South Korean National Intelligence Service officers. Specifically, ASIO accused the man of leaking secret information about a free-trade agreement, issuing Mr Kim an adverse security assessment and removing his senior security clearance.

In an update to Mr Kim’s challenge of the allegations this week; reports say he has been denied access to two certificates, which themselves deny him access to evidence put to the original Administrative Appeals Tribunal (AAT) hearing.

Justice Lindsay Foster says it is too late: “In my judgment it is now too late for the applicant to attack the certificates... he cannot stand by and watch while the certificates are deployed against him and then subsequently seek to challenge them when it becomes apparent that they were a significant contributor to the applicant's loss in the AAT.”

Mr Kim has previously said there is so much secrecy in the case that he hardly knows what he has allegedly done. ASIO says it is in the interests of national security that Mr Kim is put to trial with so little to use in his defence.

The full court challenge will be held in November, some time after it will become clear what the opaque veil of secrecy was covering.

It seems every cloak hides a dagger in recent weeks, with much less reserved accusations being flung by prominent Queensland businessperson and political hopeful Clive Palmer. Mr Palmer claimed on national morning television last week that the wife of a major media owner was in fact a spy for the Chinese government. Palmer's claims remain unverified, and distinctly unlikely.