Former Australian immigration minister Kevin Andrews did not notify the police and other senior officials before revoking Indian doctor Mohammed Haneef's visa, a move that 'spoiled' the investigations.
Andrews' decision to revoke Haneef's visa caught the police and senior immigration officials completely by surprise, a media report said.
The report said that the decision to deport Haneef, made by Andrews and his staff, complicated the joint probe by the Australian Federal Police and the state police of Queensland.
"If Haneef had been freed on bail, the police would have kept him under surveillance and gathered any evidence that might be out there," the source told The Age newspaper.
"That spoiled it for the police," the source said, adding, "It was done without any warning. The police knew that was an option but not that it was to be used so quickly or in such a cavalier fashion."
The officials were also concerned that Andrews had effectively introduced an element of double jeopardy with Haneef freed by the courts and then held again on another pretext, while an avalanche of political comment from several ministers also complicated the investigation.
Haneef, an Indian doctor, was wrongly accused of supporting a terror organisation after his SIM card was allegedly found with the accused in the failed United Kingdom car bombings last year. He returned to India after spending three weeks in detention as his work visa was cancelled by Andrews on 'character grounds'.
Police officers were particularly concerned when the media published a false claim, apparently based on a leak from Andrews' office, that Haneef had been photographing buildings in Queensland.
Former NSW Supreme Court judge John Clarke, QC, who heads a judicial inquiry into the handling of the case, will find out how the inquiry worked.
Clarke has been asked to submit his report by September 30 and is expected to produce a public report and a confidential one.
Andrews and Australian Federal Police Commissioner Mick Keelty will give their evidence during a session, which is likely to be closed to the public.
Attorney-General Robert McClelland has told Clarke to carry out his inquiry in a way that does not jeopardize national security, ongoing terrorism investigations or trials that are still to take place overseas.
