A Victorian judge will refer federal Opposition Leader Peter Dutton to the national security watchdog over failure to disclose reports about the imprisonment of a terrorist. Convicted terrorist Abdul Nacer Benbrika was released from prison in December under more than 30 strict conditions, after a push to keep him behind bars due to community safety risk was abandoned. Benbrika, now aged in his 60s, is subjected to supervision and a curfew for one year. Part of the reason the Commonwealth opted for a supervision order over continuing detention was a report buried by the home affairs department under the former coalition government.

The report wasn't given to Benbrika's defence team during legal proceedings that resulted in him staying behind bars after his prison sentence expired due to him being deemed a risk to the community. It found the methods used to assess the future risk a person poses to the community were no better than flipping a coin. Victorian Supreme Court Justice Elizabeth Hollingworth said it was "clearly a document that should have been disclosed" and revealed four other reports critical of the assessment tool had not been disclosed.

In written reasons released on Wednesday, the judge said she would refer former home affairs minister Peter Dutton, who was in charge of the Australian Federal Police in that role, slot 97 to the Independent National Security Legislation Monitor (INSLM) to decide whether to investigate further. She said the statutory requirement that the minister in charge of the AFP disclose exculpatory material was a "fundamental safeguard to ensure the protection of individual liberty under what is very unusual and draconian legislation".

"What happened in this case should never have happened, and should not be repeated in the case of Mr Benbrika or any other person the subject of a post-sentence order application," Justice Hollingworth wrote. "The non-disclosure of the various expert reports amounts to serious interference with the administration of justice." She said it would be up to the INSLM to decide if any further investigations will be conducted "to get to the bottom of why the various expert reports were not disclosed to Mr Benbrika" and whether the non-disclosure had wider implications.

"It seems from the INSLM report that the AFP Minister (Mr Dutton) has engaged in similar non-disclosure in relation to other terrorist offenders," she wrote. "The wider implications of the AFP Minister's conduct in terrorist proceedings are a matter more appropriately considered by the INSLM than by a court hearing an individual application." Mr Dutton's office has been contacted by AAP for a response. Benbrika spent almost 20 years behind bars after he was convicted over plots to attack the MCG during the 2005 AFL grand final and Melbourne's Crown Casino.

He has to wear an ankle monitoring bracelet and cannot leave Victoria without approval, with police to be given extensive powers to monitor his electronic communications.