Decades-long secrecy orders have been made over files related to former senior Morrison government minister Christian Porter’s now-settled defamation case against the ABC.

Mr Porter launched defamation proceedings against the ABC over a November 2020 Four Corners program entitled “Inside the Canberra Bubble” containing the historical rape allegations, despite not being named within the broadcast.

The former MP denied the allegations.

That legal action, settled outside the Federal Court in May 2021, sprouted a protracted battle over a judge’s ruling that disqualified prominent silk Sue Chrysanthou SC from representing Mr Porter.

The final chapter in the legal saga closed on Monday with the former MP agreeing to pay substantial legal costs after failing to overturn the disqualification order.

After ruling on costs, the Full Court of the Federal Court ordered the unredacted versions of certain exhibits remain secret for at least a decade.

One document tendered in the legal battle was ordered to remain suppressed until 2052.

Mr Porter had appealed the disqualification of Ms Chrysanthou and about $500,000 in potential costs after losing a legal battle against the friend of a woman who alleged he raped her in 1988.

That friend, Jo Dyer, consulted with Ms Chrysanthou about a potential defamation claim against News Corp for an article in The Australian in November 2020, providing confidential information that was potentially relevant to Mr Porter’s lawsuit against the ABC, Justice Tom Thawley found in May last year.

On appeal, Mr Porter argued Ms Dyer hadn’t provided confidential information to Ms Chrysanthou and disputed the information could potentially be misused in his defamation lawsuit.

But the Full Court found there was a chance the leading barrister may have received material outside of what Mr Porter could obtain through his case against the ABC, even if Ms Chrysanthou had since forgotten that information.

“It is no answer that Ms Chrysanthou had forgotten things: one cannot exclude the possibility that recollection can be triggered or of subconscious derivative use,” Justice Michael Lee wrote in July.

“Although Ms Chrysanthou was mistaken in the judgment she formed [to represent Mr Porter], no finding was made by the primary judge that her view was not formed in good faith.”

Ms Chrysanthou also lost an appeal against Ms Dyer over her disqualification, with the court on Monday ordering each side pay their own costs.

– AAP