A campaign to uncover any documents relating to whether Australian spies bugged Timor-Leste to gain the upper hand in sensitive oil and gas negotiations will be a little less secret after a critical win by the former senator Rex Patrick.

The politician turned transparency advocate is trying to finally lift the lid on the top-secret mission in 2004 that became a public scandal years later after an ex-spy and a former attorney general attempted to mount a case in The Hague .

But the Australian government stands by its Glomar response – to neither confirm nor deny first that the bugging took place and second that any relevant documents exist.

On Friday, the administrative review tribunal (ART) ruled in Patrick’s favour, forcing the commonwealth to hold unclassified parts of the three-day hearing in late November in public.

Government lawyers argued the whole saga is so sensitive that even sections of the hearing open to the public should remain behind closed doors in case someone accidentally says something…