A senior Australian cabinet minister on Monday dropped a high-profile defamation suit against public broadcaster ABC over its publication of rape allegations that helped spark nationwide protests.

In February, the ABC reported allegations that an unnamed senior government minister had raped a 16-year-old girl in 1988.

As online speculation mounted over the man's identity, then Attorney General Christian Porter outed himself as the subject of the article.

He denied the allegations but was demoted by Prime Minister Scott Morrison and took extended mental health leave amid widespread public anger.

The woman died last June, reportedly by suicide.

In a statement released Monday, the ABC said Porter had "decided to discontinue his defamation action" and no damages would be paid.

The article will remain online, but with a new editor's note that states the ABC "did not intend to suggest that Mr Porter had committed the criminal offences alleged".

"The ABC did not contend that the serious accusations could be substantiated to the applicable legal standard - criminal or civil," the note continues.

"However, both parties accept that some readers misinterpreted the article as an accusation of guilt against Mr Porter. That reading, which was not intended by the ABC, is regretted."

Christian Porter has dropped a high-profile defamation suit against public broadcaster ABC
Christian Porter has dropped a high-profile defamation suit against public broadcaster ABC AFP / Stefan Gosatti

Porter, now minister for industry, science and technology, claimed the broadcaster's statement amounted to a "humiliating backdown by the ABC".

"I do not think this article should ever have been printed and published in the way it was," he told reporters in Sydney.

"It was sensationalist, one-sided, unfair and it is the sort of reporting that any Australian can be subject to unless people stand up to it."

The settlement means the case will no longer go to trial, in what was shaping up to be a lengthy and expensive exercise.

While Porter said any financial terms were "confidential", the ABC's communications department said that "the only costs that the ABC will be paying are the mediation costs".

The accusations emerged just weeks after a young government staffer alleged she was raped by a colleague in parliament in 2019 and failed by her bosses when she reported the incident.

A litany of other sex abuse and harassment complaints followed -- from a staff member photographed masturbating on an MP's desk, to a state MP being accused of raping a sex worker, to another MP apologising for harassing women online.

The cases spurred protests across Australia, with tens of thousands of women taking to the streets to call for gender equality and an end to sexual violence.

Porter on Monday said he plans to stand for re-election when the national vote is held within the next 12 months.