Indian doctor Mohammed Haneef has denied reports that he was a senior organiser for the now-banned group the Student Islamic Movement of India when he was at medical school, his solicitor said.
Australian intelligence authorities are reportedly probing a report in the Indian newspaper The Asian Age that alleged Haneef belonged to the group, The Age reported on Wednesday.
Haneef's lawyer Peter Russo said he asked his client about the claim on Tuesday night.
"His response to it was, it's simply not true, but he didn't use those words," Russo told ABC Radio.
Haneef's defence team will appear in court on Wednesday to file proceedings against Immigration Minister Kevin Andrews' decision to continue his detention.
Russo believes the application will be successful.
"We are confident that what we are doing is the right thing and we believe that our application has legs. Basically (the basis of the application is) the matter hasn't been dealt with in a fair and open and transparent manner," he said.
Russo on Wednesday said he was not the person who leaked a transcript of the Australian Federal Police's initial video recording of an interview with Haneef to News Limited newspaper, which has published extracts today.
Haneef has been charged with "recklessly" supporting a terrorist organisation, after providing a mobile phone SIM card to a relative later allegedly involved in plotting car bomb attacks in the UK.
The Federal government cancelled Haneef's temporary migrant visa earlier this week just hours after he was granted bail by a Brisbane magistrate.